I've lived here for close to ten years. Overall Summit Hill is great. Very spacious apartments, nice grounds and amenities, well maintained.
Noise can be an issue, particularly in terms of upstairs/downstairs neighbors. Even if you're on the top floor, you will hear the people below you. Your satisfaction with your apartment will depend heavily on who your neighbors happen to be, whether they have screaming kids, etc. If you wind up with the wrong neighbors you'll be counting the days until you move out. But I suppose that's true of most apartments in this price range.
Summit Hill has a full-time maintenance crew, who you will see running around in trucks and golf carts every day. The turnaround time on maintenance requests is excellent.
The pool is really nice and surprisingly underutilized.
The location is great, unless you need to commute to NYC, in which case living here may not make sense.
Overall, I recommend.