I agree , It's a long learning curve this GPU computing stuff
This stock application is faster on my machine then opt app. Difference is speed is from 10-15% per results with low credit ( fast result) to 1-5 % per result with high credits (aprox 110 credits)It also seem that this stock app works better on my GT 240 compared to second comp with GT9800 ( or maybe it is driver thing ( 196.21 WHQL)
I am also running crunch3r's seti linux cuda, tho right now, there are no wu's aviailable. That one uses 2.1 lib and I tried 2.2 but got an invalid signature. I didnt bother with 2.3.