Diver, this is the website that was a lot of help to me in making the decision.
http://www.tiggerpoz.com
When the vet told us that there was better than a 50% chance of the other side going within a year I knew we needed a better alternative than surgery.
Fed her lots of glucosamine (still do) and got her thinned down quite a bit and life has been good.
Good luck whichever way you choose.