Liam, there is no right or wrong answer to your choice of a valve. I did my research and decided on an on-x valve. I did have trouble finding a Dr. here in the Seattle area that would implant one. Found Dr. Glenn Barnhart at Swedish Medical Center, Cherry Hill location, Seattle. That is the only valve he uses. Out of the three Drs. I interviewed, he was the oldest but the most up to date as far as I was concerned. He has done thousands of AVR's. He was the man for me and he used the valve of my choice so I did my surgery on May 23, 2013 and couldn't be happier so far. Coumadin is still trying to be adjusted. No problems so far. Good luck with your choice and know it a personal one. - Kim