Yes I have and it is good value and works a treat. Not quite as nice as the moonlite perhaps, but way way way better than the built in focuser.
If you want to try one out, I can post you one to play with for a while, PM me your details.
You could mod your scope to have mirror locks, this is the best solution I have seen.
http://www.marsastro.org/presentatio...irror-Lock.pdf