We are frequent travelers to Las Vegas (2-3 trips/year), and have stayed at Mandaylay bay at least 5 times in the last 2 years. This time we chose to stay at THEhotel. We were traveling with a one year old, so it is nice to have both the sitting room and bedroom in the suite. The rooms are quite comfortable. They are not along the lines of what you will find at the Wynn, but they have plasmas, DVD player, iPod dock, etc. Comfortable beds, nice bathroom--although they are in need of some rehab. The carpet was showing its wear and some fraying on the arms of the chairs, etc. I would not call this a first class hotel, but it is a good value for the dollar in terms of space. The pool at Mandalay is great and there are many good options for dining and entertainment. It's at the quiet end of the Strip, so less crowded.
That said, we will not return to THEhotel. When we requested our pre-requested adjoining rooms (we are a family with two older children an infant and a pre-schooler) at check in we were told they could not accommodate us. They said that then entire property was sold out for the duration of our stay--we might even need to take rooms on different floors. After a half hour of wrangling with the desk clerk, she finally consulted a supervisor and they "found" two rooms. However, they could not confirm that we could have those rooms for an hour and a half, so they asked us to return to the desk at that time for check in. When we returned, we were told that we would get the rooms, they were not clean yet, but we could have them by 3:00. (I understand that 3:00 is the official check in time.) However, I also learned that the property was only 87% filled at that time. (Not surprising, considering the economy's impace on travel.)
Other issues:
-Room service late (+15 minutes) 2 out of three times ordered
-Broken make up mirror in bathroom
-Hair dryer stopped working on day 2 of stay
-No children's offerings on room service menu (they did make a grilled cheese upon request)

this hotel is new and very contemporary, with a nice and clean feel to it. it is located on the main strip of vegas, with other hotels. american express gave us a good deal .the bath house spa is a good one. they have a nice big casino, an in huse shop. this is connected to the other hotel- mandalay bay, thats the old wing. but a nice place to stay.

We went to LV with our 9 year old and booked the Mandalay because of the pool. We ended up being upgraded to THEhotel - lucky us! The rooms were large and clean. One of the best things is the bathroom. There are two sinks, huge bathtub and a television. My son thought it was the coolest thing ever to take a bath and watch tv at the same time - I could barely get him to leave the room. The room was very quiet, I only heard noise on our last day and even then it was very low. The casino was great, it seemed to be a lot less smoky than the other casinos. The downside is the location - be prepared to walk or take a cab if you want to visit other properties. Overall, I would definitely stay at THEhotel again.

Stayed at THEhotel for 4 nights. The rooms were spacious, comfortable, and a great place to relax after roaming the strip. Stayed at Mandalay for the pool and it was truly an amazing pool area. THEhotel is not that far a walk from the casino and getting around the hotel is fairly easy. The one drawback is that the Mandalay Bay complex is the southernmost hotel on the strip so getting to other hotels required a good bit of traveling by foot although the tram to excalibur helped a little. The price was great and I would definitely say these are up there with the top rooms in Las Vegas. I highly recommend this hotel to anyone.