The Venetian is pretty nice. The decor is nice. The rooms are pretty standard from what I remember--and sorry, I don't remember much because I wasn't exactly sober the entire weekend. Oops...
I really hate that you have to walk hella days just to get anywhere in the hotel! The casino areas can get quite crowded, even to the point where you have to start holding hands with the people you are with.
The Grand Canal Shoppes are pretty cool--it always feels like midday. The gondola ride is a waste of money unless you can get your gondolier to sing you Italian opera. I've gotten lucky and had them sing arias to me both times I've ridden them.
If you plan to stay at the Venetian be prepared to walk around a lot. I know that in Vegas, walking around is expected, but methinks the Venetian is designed to confuse people so they walk around more and buy more shit. Be careful!