What is the advantage of M2 over doing setup-moves and U-perms (that would be called freestyle, I think)?
I learned M2/R2 some weeks ago and I am averaging around 5 minutes now. I tried U-perms once and it took about 10 minutes, but due to the fact I am not used to the setup-moves I think this was quite OK. So what is the advantage of M2?
The advantage is that it is "braindead", meaning that it can be executed very fast, since you may know exactly what to do for every letter/sticker. For every non-M-slice piece it's 5 or 7 very easy moves, which when practiced can be done very fast.
Also, the M-slice pieces is actually very nice to solve if you're using a good method for them.