Three of my girlfriends and I stayed at the Beach Palace the week after Easter. We were treated like royalty and had a wonderful stay. The staff went out of their way to learn our names and take care of us. Guest rooms are very nice and plenty spacious, even with that double jacuzzi taking up space (and going unused in our case). The large balcony was a HUGE bonus and a great place to enjoy an afternoon cocktail. We had maid service twice a day, so we never ran out of towels.
The food was reasonably good. I don't think anyone goes to an all-inclusive resort expecting to be blown away by the food, but I was pleasantly surprised by the quality and taste. Breakfast however far EXCEEDED expectations with an omelette station along with made-to-order waffles, pancakes and french toast. There is also cereal, fruit, yogurt, etc. Breakfast was my favorite meal of the day. The lunch buffet was fine, we usually made salads from the bar. Their guacamole was also excellent. For dinner, we ate in the Asian, Italian and grill restaurants. I liked the grill a lot (grilled shrimp were great!) while my friends thought the food was a little salty. We all agreed the Italian was disappointing. The Asian was quite good. We also ate at the Asian restaurant at Cancun Palace and thought the Beach Palace's food was superior.
The one downside of Beach Palace, at least while we were there, is there was NO beach. I understand from other posters that this varies from day to day due to the tide. However, in the 7 days we were there, not once could you walk out to the beach. We felt like we were stuck on a cruise ship - looking out on the beautiful turquoise water but not being able to get to it. This was even more challenging since the front of the hotel opens onto a busy 4-lane road that isn't really conducive to walking.
As mentioned, you can easily get around Cancun on the city bus, so we took exploratory trips to the Sun Palace and Cancun Palace. Sun Palace is adults only, seemed kind of quiet. However, they do have a nice beach. Cancun Palace was huge (rows upon rows of pool chairs) and felt less personal than the Beach Palace. It also did not have a beach.
A previous poster noted that they took $100 in singles for tipping, and we did the same. I thought that was money well spent, particularly given the EXCELLENT service we received. The other tip I would note is that if you got the promotion where the "Swim with the Dolphins" was included with your trip, note that you have to book this separately from your trip to Isla Mujeres. So the vacation planner books your trip to IM (which is a disappointing place to visit, in my opinion), but then you have to SEPARATELY book your excursion. This was not explained to us even though we said we wanted to use our swim with the dolphins package, so imagine our disappointment when we got to IM but weren't reserved.
In general, I really enjoyed the Beach Palace and would recommend it, with the caveat that a week without being able to walk on the beach is difficult!