I have to agree with Geoff and Mark, for the cheap GSO focusers it's just not worth it.
I really dislike the GSO focusers, especially when trying to focus with the webcam in the hole. Everytime you try to adjust focus the whole thing wobbles in the FOV (cause of the high power) and you can't even tell if you're bloody in focus.. and by the time i've finished adjusting it, the star has moved off the FOV of the chip!
As Geoff said, the trade off of stiff focussing or sloppiness in the barrel.
I can't wait to get my moonlite, it didn't arrive at my doorstep today - hopefully tomorrow..