I'm curious if you have blown these yet or have they been reliable?

I think if the stock valves are in good condition you should be fine, they are fairly cheap and easy to get at so you can change them at regular intervals. The APR R1 valves are a nice piece of machine work, and I'm sure they will last a very long time. Under partial boost they tend to make honking noises that are quite noticeable and a little embarassing.

Specifically, APR response to my inquiry into this issue is as follows:

"If the R1 is honking, they need to get it warranty replaced. We have a lifetime warranty on these, and honking is not normal! That simply means that they need to get the spring inside replaced. =)"

I am considering this valve and thus asked APR the question when I saw your post. I thought this might be helpful to you as they state they will replace under lifetime warranty.