We stayed at the Poly for 8 days in February. While I wouldn't trash the place it certainly isn't my favorite. A couple of things I liked first:
1. Location - it's great to hop right on the monorail and get to MK or walk to the TTC.
2. Cleanliness - the rooms were kept very well
3. Lobby - sitting in the lobby and listening to the waterfall is very soothing and relaxing.
4. Kona Cafe - the restaurant was delightful with very good service and the food was yummy. They were able to seat us at busy times with not much of a wait.
Things I didn't like:
1. The pervasive gas smell - I suppose from tiki torches that were not lit or out for some reason. Anywhere you walked there would be a strong odor of gas.
2. Dining options - if you are only there for a few days it may not be a big deal but the two restaurants are insufficient for a resort of that size.
3. Electric carts! This one really chapped me. The workers in those carts speed around the walkways like they own them. You'd be walking along enjoying the scenery when "screeeech!" one would come around the corner and almost mow you down. The CM's were very nice, but I think they should have designated service paths. This was a big negative for me.
4. O'hana - we had to wait 45 minutes the one time we had a PS, and the food was marginal at best. I'm not sure if we caught it on a bad day or what, and I like to eat somewhere at least twice before I give it a bad review, but since that's impossible I can only tell you my one experience there.
All that said, I think you will have a great time. Just go in knowing about these little things and you will still enjoy it.