I don't know how true it is, but I thought I heard/read that OS is more aggressive in younger hounds.
But, I will let you know, that I went the amp route with my 12 yr old Diamond. It took just 2 weeks for her to be almost 100%. While we only had 6 months, it was a very happy, pain free 6 months.
It's a very very difficult decision. But remember you're doing it out of love.
Good luck. Keep us posted.
PS....you're only about 11 hrs from OSU. I drove from NJ to Ohio to have them do Dima's amp. I did not regret a moment of that.