Tommy, interesting observation on Briess. When I said "poor" performance I really meant "inconsistent," you seem to have observed that. Briess operates on a small-batch scale compared to Rahr, which is one of the world's largest maltsters; that may be a factor in variability. As for availability, I suspect that's something to do with your retailers. Again, Rahr is huge, and owned by BSG, the US importer of many brands (Weyermann, Castle, Crisp, Simpson's, Patagonia, Gambrinus, Malt Co of Ireland...) your shop probably carries.
And yeah, Briess gets out of the way, I think Rahr has more presence, which I guess I like. I've not had the opportunity to try GW.