We just stayed at the FS Sayan and then the RC Jimbaran.
The FS Sayan is, without a doubt, the most outstanding property we've ever seen (we stayed in Villa 21, infinity pool overlooking the rice field and river). We have been to Lizard Island, Hotel Bora Bora, all around the world and we thought Sayan was the most special. I can still smell the flowers everywhere and hear the music.
Ubud was wonderful. We stayed there first for 6 days, and then went to RC Jimbaran. We were SO disappointed.
Yes it is a beautiful hotel (the RC). But it is just that....a GIANT luxury resort. It felt like we could be anywhere, it didn't feel like Bali. Could have been in Naples Florida, or anywhere there is a giant resort that some people never leave. We stayed on the club floor, by the way, which was good. But not AMAZING and SPECIAL and MAGICAL like the Sayan.

Also, the RC really is far from everything else. It is a long ride to get anywhere. I would not stay there again. We would probably do the FS Jimbaran or one of the newer beach hotels opening up. This months Travel and Leisure and the "new asia" article mentions a few new places opening up.