I doubt it would work on your SGS2. Having read the instructions it scared the crap out of me. I'd stick with CF Root.
Out of interest, why are you trying to root your phone? If it's to allow you to update your rom to a new OS version then I would seriously recommend that you use CF Root because you will want to use the utilities that come with CWM to back up your phone before changing rom.
I doubt it would work on your SGS2. Having read the instructions it scared the crap out of me. I'd stick with CF Root.
Out of interest, why are you trying to root your phone? If it's to allow you to update your rom to a new OS version then I would seriously recommend that you use CF Root because you will want to use the utilities that come with CWM to back up your phone before changing rom.