Thanks for the info guys. I know that folks have had syncro issues with their WRX's, and I know partly it's due to the metallurgy involved. I think that what we refer to as, "mechanical sympathy," on the team might be lacking in a lot of drivers as well.
Folks that are shifting quickly(drag, fast street, etc) are perhaps shifting a bit too optimistically for the box, causing premature wear. Of course, when you buy a used WRX, you should assume it's been spanked pretty hard anyway! ;-)
We have several Subarus on the team. As you know, we're on #4 rally car. We've NEVER had a tranny problem(except breaking teeth off gears due to hitting large, stationary objects). Now, some of this might be because we're on lower grip surfaces than most of you, but with our gravel tires, our grip(and our torque levels) are pretty high.
So, why all the problems on the street? I don't know. We've run MOTUL exclusively the past few seasons. Prior to that, I ran other common products in our Honda CRX rally car.
It seems excessive to me that folks are scouring the net looking for ingredients to put in their trannies, when a high quality product might be all you need.
The other part of the issue: once your syncros are bad, they're bad. Time to open the box and replace them. No fluid is going to help you.
Cheers! John