I did 5 days with Mitchell. They won't force you to do stuff you don't want, but very good for support. It didn't change his sleeping too much, but gave me a HUGE sense of confidence. I use a mix of their technique and my heart. Things did get better - then his teeth came through, he got sick etc, etc. Nearly over now so we are going to put the routine back in place.
There is nothing worse than not knowing WHY he wouldn't sleep well (he was pretty shocking).
I'm sure you'll get alot out of sleep school - especially sleep!