I stayed at the Viceroy a few years back in the Viceroy villa. Sublime and highly impressive. One of my favourite hotels ever. I agree on the redemption not being overly valuable but sometimes the viceroy rates are sky high. Points could be worthwhile during these times. My experience with the hotel is that you should negotiate upgrades. they are family run so income is income. worthwhile for sure on arrival.
I have stayed in a whole bunch of hotels in Ubud. All were great. My favourite though is Capella. It is more than a hotel stay it is an experience. A must do in my mind if you visit Ubud.