OK Marriott - nothing to get excited about
I stayed two nights at the hotel, and was impressed when I entered the lobby, the ambiance felt like a W property. However, once you leave the lobby, there is no mistaking this is a cookie cutter Marriott property. The elevators are extremely crowded in the morning and afternoon, and they seem to stop at every floor, so a ride to or from the executive lounge on the 26th floor is not a quick trip. 
The rooms are ok, but again nothing to get excited about. It is strange to go from the trendy lobby, complete with club type music, to your room which is the old school Marriott color scheme, complete with blue carpet and somewhat dated furnishings. My room had a small refrigerator setup in it (forgot to remove that request from my profile), however they never bothered to clean it out from the previous guests, and it was full of old food and drinks, pretty disgusting. 
The executive lounge has a nice view of downtown and the airport, and there is a patio to sit on which was nice in the morning. However, the patio was constantly in use by smokers during my visit, so unless you don't mind sitting in a cloud of smoke, it loses it's charm fast.
The service at the restaurant for breakfast was not too good, had to wait for 15 minutes before being waited on and that was only after I went and found a waitress. I then had to listen to two waiters argue with each other about who is supposed to work certain sections. The service at Tanq was not much better, waited 10 minutes there and never was asked if I wanted to order something so I left and went to Il Fornaio across the street. 
The final indignity for me was that even though I had wifi access paid for through my room, this access is not available on the conference room level. So unless the conference you are attending pays specifically for conference room wifi access, you have no internet - and if you use AT&T, there is no signal on the conference room floor, which means a day of no email access. The chairs in the conference rooms must be from the 80's, because they are so worn that you can barely sit on them.
My take on this hotel is that they get a guaranteed revenue stream from conference guests and convention center guests, so they don't have a lot of incentive to go out of their way.