We stayed at Vidanta's Mayan Palace, it was a great trip and I highly recommend it. The resort is amazing and lush with wooden walkways throughout, and shuttle service all day (so don't be disappointed if you get a building that's farther away from main pool area). The kids enjoyed the flamingo sanctuary and crocodile sanctuary. The pools are amazing, with plenty of kid-friendly pools and areas. The service was great, every restaurant we ate at had great food (Green Break, the street taco restaurant by the golf course was our favorite), and the boutique (Jade) was so convenient with groceries, basic amenities, and even a nice wine/beer/alcohol selection. I was actually very impressed with the quality of the restaurants and to-go cafes there; usually the resorts don't try very hard knowing they've already got you there. The sandwiches/paninis and crepes at Jade were awesome, and later we discovered the cafe in the spa building, which also had great sandwiches/smoothies, etc. The breakfast buffet was also great, and if you got there before 8:30am, there is a 25% discount (so it came out to be ~$14 per adult for a fabulous breakfast, our kids were free, ages 2 and 4) - it was probably a good thing we didn't discover this until later in the trip, as I would have wanted to eat there every morning!
We stayed in a 1 bedroom suite, with four of us, and it was plenty spacious. The service in the room was amazing, every time we called for something, it was delivered within 10 minutes, with a follow up call to ensure the service was received (I was quite impressed with this detail). The room needed a little bit of an update, but it was clean and comfortable. My only complaint was the sales pitch for buying a timeshare there (they will start as soon as you check in), and bothered us for the first two days (by phone after you check in) - we eventually unplugged the phone except for when we needed to use it. Eventually, they stopped calling...so just keep saying NO, and it'll be fine.
Our experience booking with Stephen was also fantastic! This is the first time I've booked amenities through a service like this, so I was a little nervous at first. However, Stephen was extremely responsive - by far the most responsive of at least 5-6 postings I inquired about. Note that the posting says it requires 6 months in advance, but I reached out about a month in advance and there happened to be availability - so don't let that deter you from inquiring. We were very pleased with the whole experience, and are hoping to plan another trip back soon!