Sterling used to be a great bang for the buck, a hidden gem almost, some years ago, but it feels it's not anymore. It still is good, I recommended this apartment to numerous friends (and multiple friends actually have moved in), but the rent is rising and other new buildings are/have been opening around, so not very sure of its competitive edge these days.
Here are the good things - The location is great- close to everything, including the 30th st station, Art Museum, shopping and work. Shuttle services to University City and Saturday shopping shuttle (shared with AIMCO's Park Towne APT) is convenient. Gym and rooftop pool is newly renovated and look great. Maintenance is very responsive, effective and efficient. Having your own washing machine and dryer in your unit is very handy.

I have been living in this building for five+ years now- Moved within the building once. This reflects my satisfaction (so far) with this building.

Here's my warning - First, none of the utilities are included - water, electricity, HVAC, trash etc. That can add on to your rent, up to ~$200 in winter for one bedrooms. HVAC/heating is by the building, then divided based on the unit size, so in my opinion you do not have much financial motivation to save energy.
Also, renovation is going on floor by floor, and my floor is in line for renovation fall next year - so this will be my last year here. I don't know if they would do the same when you move in, but make sure your floor isn't going to be renovated within your lease - my friend moved in August 2014, moved out in March 2015; AIMCO never said anything about her floor going into a renovation. She was only informed of the fact 60 days before the construction starts and had to find a new home quite hurriedly - which fortunately worked out, but it could have been worse. Similar thing almost happened to my other friend - he was asked to renew his lease, which would last until July, and only when he asked they told that his floor will be renovated in Jan 2016. So the lease will not be the full lease - and he also moved out. It might not matter if you are looking for shorter-term lease, but for students, we are looking for something that can cover at least the academic year. At least, the residents should be well informed about the schedules. Leasing office people are in general very nice, but they have some room to improve in the communication.

In some, convenient location, pretty well managed building; but do compare well with other available options. It seems Sterling is not as competitive rent-wise compared to others these days.

I was a little leery of going north of Market Street because of all of the famed Rittenhouse Square nightlife and social scene. However, I don't feel like I am missing out at all at my current location at the Sterling on JFK Blvd between 18th and 19th.
Here are the reasons why I like my apartment:
1) Space and value proposition: we have huge floor plans relative to what I've seen near Rittenhouse Square. I personally visited several brownstones, 1930 Chestnut, RiverWest, and Wanamaker for my search. I think this is by far the best value proposition for your dollars. The units at the Sterling are a bit like a less luxurious version of Wanamaker, without bay windows. Also, I have been to the Icon and 2116 Chestnut, and those apartments are undeniably more luxe; however, I am happy just visiting those buildings for social events, and saving a few 100's of dollars a month living in my building. In my 2bed/2bath unit at the Sterling we have a large living room where we can host people for working together, pre games, having dinner, etc.
2) Responsive management and an e-portal for maintenance problems: We have a website where we can report maintenance issues and we usually get a response and a technician coming by within 1-2 days. The electronic communication is nice and seamless.
3) Close to the trolley: the fastest, most direct, and economical way to get to campus. Trolley (subway) is great. I take it from 19th & Market.
4) Close to Trader Joe's: the Trader Joe's near 22nd & Market is where I go for almost all my groceries.
5) Pretty modern appliances and in-unit fixtures: For the price we're paying, we have pretty good in-unit washer/dryer machines, dishwasher, a large kitchen, good amount of closet space. I don't feel like I have too little closet space or storage space at all.

There are a few things that could be better. 1) Wish it were closer to 2401. We do get a lot of team meetings and some social events scheduled at 2401 Walnut, the student lounge and co-working space. On cold nights it is a bit of a drag to trek over there.
2) The gym: we have an interim gym currently because the building is undergoing major construction and we are supposed to have great new gyms and patios and lounges in 2015. I hope the project gets finished on time. It's kind of hard to make myself go to the gym at Pottruck or go far to exercise. 3) Pet rent is $50/month, but I love my cat so I pay it.

The price can't be beat: $2,750 for 3 large bedrooms and a great living room (1,600 sq ft) in a high-rise, doorman building
. The Management is very very slow to respond to maintenance requests (e.g., we had a cabinet with water damage that needed to be replace upon move-in in early August, and it was finally completed at the end of October). Beware of living in a unit that faces north, as construction for the new Comcast building starts at 7 AM Monday through Friday, and at 8 AM on Saturdays
. The building is one block from the trolley on 19th & Market, which is really fast (always 10 minutes) and runs frequently, so the commute to campus is 20 minutes (tops) door-to-door
. The business center is nice (free wi-fi) and serves as an alternative meeting place to 2401, but the printer hardly ever works

Renting one of the older units that have not been remodeled. For the price, an excellent deal. Also, the apartment is on the Market St trolley, making convenient access to campus.
The downside is the noise. If you are on the north side of the building, there is a Comcast tower going up for the next 3 years so you will constantly hear loud construction noises 6 days a week. On the South side, regular city noises. The management is generally accommodating helped us transfer the lease from the north to the south side.

The apartments are huge, and that is great for families, especially in the winter. It doesn't have so many amenities (under current construction) but overall is the best one in terms of sq.ft / price

Huge apartment, tons of closet space, gym and pool. 1 block from trolley. Online rent payments

There is a rooftop pool and good gym. There is 24hr security and a doorman who receives packages. The apartments are very large and spacious. Full kitchen with dishwasher, laundry (washer/dyer) in apartment, several extra closets for storage, space for several couches and a dining room table. Maintenance is very responsive ... can replace a lightbulb or a broken refrigerator on the same day you submit a request. Some of the larger/three bedroom units have balconies. There is a Trader Joe's 3 blocks away and a well stocked independent grocery across the street. A few things people might consider a drawback ... the apartments that face south look right into office buildings across the street, the fire alarms are extremely annoying and go off often in the middle of the night, the toilets in the building are old and have a tendency to run. Additionally, the location is not the best in center city ... it's a bit far off Rittenhouse to really be right in the middle of things, and there aren't many good restaurants close by. On the whole, however, I would definitely recommend this apartment building.

Good value for the money. Convenient location. Spacious apartmet. Two minitues walk to trolley.

Very spacious rooms and friendly staff. Convenient to the trolley for commuting to school.

The Sterling is a very affordable option within Center City. The residence is one block outside of Rittenhouse, which will make you slightly outside the Wharton bubble. However, all Rittenhouse locations are really easy to get to and the building is centrally located to a lot of other good Philly spots i.e. Reading Terminal, Art Museum, Logan Square. You are also one block away from the regional rail line and the trolley. The maintenance staff here is pretty bad and the building is old. Although I have not had any major issues in the apartment that would make me really mad about the maintenance staff. I am married, so having a washer/dryer unit in the apartment was definitely a plus for my wife. Also has a good pool, workout area, and business center.