We stayed in a standard room at the Wynn for 4 days in early July. The standard room is nice, on par with the Bellagio standard room, but smaller than the Venetian standard rooms, which are larger suites. We only ate at two different places at the hotel (Terrace Cafe - 24 hour; and Bartolotta, a seafood restaurant). Both places served good food, but the service was lacking. Our first visit to the Terrace Cafe was at 1:30 AM and they told us the wait would be 15-20 minutes! What? There were many open tables and not many people there! Why the wait? On our second visit at 4:30 PM, we waited about 10 minutes after being seated before anyone showed up to take our order. At Bartolotta, we were told the reservations were running 15 - 20 minutes behind, yet when they sat us at our table, there appeared to be several other open tables. Otherwise, Bartolotta was a wonderful, although pricey experience, but well worth it. The other service issue involved housekeeping not cleaning our room one day until we made repeated requests for them to do so.
My other gripe was that they had no pricing for things like facials, massages, and other services on the web. You had to call so they could send a price list. I thought the prices were steep even for a hotel of this class and my biggest gripe was that they wanted to charge $25/day (or a 3-day pass for $65) to use the gym even though it is only for hotel guests.
The hotel and casino were very nice, clean, and relatively uncrowded and our overall experience was a good one. However, I think you'll get more for your money in terms of amenities and service at the Venetian or the Bellagio.