Nick, funny you should mention the Diapasons - that's what I have! So you know the kind of reputation the Bedini / Shahinian combo has. All I can say about the AVA is that I have no burning desire to go back.
As I'm sure you already know, the beauty of van Alstine's gear is that you can try it with a money back policy (excpet shipping, of course). If you can swing a trial it might turn out to be the right ticket. Or put up a post on the van Alstine circle asking if there are any FetValve owners in your area.
