The Ritz Carlton in Jimbaran Bay is pretty nice, but I wouldn't consider it to be one of Bali's best hotels. The owner's ran a little short of cash prior to completion and if you look closely, you can tell.
As one would expect, the staff is all first rate. The spa has just undergone a major expansion, but I haven't seen the completed product. One thing about the property that surprises many people is its lack of a beach. Actually, there is a beach, but it about a 1/4 - 1/2 mile walk (the hotel will give you a lift). Once you get to the beach site, you have to descend an extremely long, steep stairway down a cliff, and I've seen some people having trouble making it back up at the end of the day. A new GM was brought in last year, and I believe he's making some positive changes.
Overall, it's an excellent property-- but a find it a notch below what I would normally expect from a Ritz Carlton. I have only seen the Four Seasons Sayan from the air (helicopter), but the property looks spectacular. I have heard nothing but good things from people who have stayed there.