my wife and I didn't do the class. We both had about 75 or so, mainly cold water dives (great lakes). When our Seaskins showed up, we borrowed a copy of the coursework from a buddy, completed all the reading/videos, and headed of to our local Scuba park. We worked through the exercises, and weighting, in shallow/confined water, with the help of an experienced diver. After a couple dives like that, we progressively went deeper as we gained comfort and familiarity. It wasn't much of an adjustment to be honest, but we dive regularly at home, and work on skills often.
My 2 psi..... If you're not a complete novice diver, and you are willing to do some learning on your own without someone holding your hand, it is totally doable. Take your time and find a mentor to help you out.