Disclaimer - this was my first time in Vegas so my review is more a comparison to hotels in general, rather than Vegas hotels. Also, I did not make use of the Spa (Canyon Ranch) or go to the pool.
First, the hotel complex is HUGE and there are actually three separate properties: The Venetian, Venezia Towers and the Palazzo. We stayed in a Bella View Suite in the Venezia. The Venezia has a smaller, less busy check-in counter that is not clearly pointed out. You can check in for either hotel at either check in. Upon check in at the Venezia they offer an upgrade the the Venetian (rooms more recently modeled, wireless net) for $20 or the Palazzo for $40. We chose to stick with the Venezia since none of the properties are very old and the room had ethernet internet. There is a $17/day mandatory fee regardless of where you stay.
The suite was very nice and came with either one King sized bed or two Queen sized beds. There are three flat screen TVs (bed, lounge, bathroom). We were missing one remote and the bathroom remote was out of batteries. Otherwise the room was in good condition at check-in. There were also extra pillows and iron/iron board in the closet. The bathroom was truly spectacular, lots of towels, one terry robe, and some q-tips, cotton balls etc. The shampoo, conditioner, and soap was deliciously scented.
I noticed the furniture was a little worn looking, especially the couches. Also the TP holder in the commode kept falling out and clanging on the marble floor. I imagine that Vegas hotel rooms have a lot more activity/use so things wear out faster. In addition they don't include a kettle or coffeepot in the room. Room service can send you a kettle. Be aware that there is a $4.95 delivery charge for room service and it takes about 20 minutes for them to come, not including time taken to make the food. The rooms have a free safe which we used and were satisfied with.
Other ammenties in the hotel are the Spa + pool, LOTS of restaurants, a casino (and the Palazzo casino is a short walk away) and LOTS AND LOTS of shopping. The Venetian is one of the more family friendly hotels and entertainment is not so focused on just gambling. Hence the numerous shops, restaurants, nightclubs, etc. The indoor canal, walkways and center square are really cool - it's feels like midday no matter what time! I also appreciated seeing security around and after a certain point they start asking to see room keys to walk through the "residential" parts of the hotel - no drunken randoms roaming the halls.
Note: a lot of reviews pointed out the strong rose scent. It is strong the first time you enter the building, but not present in the guest rooms. I don't mind the smell and didn't notice it after the first day. Treasure Island also does the same thing.