Pillow top are great. Had ours for about 7 years now and the best sleeps ever. You sink down in them a bit and it does tend to leave an indentation over time. So I mark each end, top and bottom, of the mattress Spring, Summer, Fall, Winter, then flip the mattress at the end of each season. That way it gets even use.
I learned this trick from my son when he worked at a high-end hotel.
Hmmm, time to flip that mattress soon.