It's not the form so much as building up the muscles as quickly as possible. I spend two hours each weekend with my coach and he inspects the form pretty closely. I do sets of front squats every time I do O lifts, which is around 3x per week. But I also want to do back squats -- feels like it works the muscles differently, maybe I'm wrong. I'm at 195lbs on back squats and 135lbs on front squats, and both need to come up. Well, actually I'm at 187lbs on front squats since that's what I'm squat cleaning so go figure....
Actually on the form, it's pretty different according to my coach. As long as I maintain the lordotic arch in the back, he's ok with me bending forward at the waist with a back squat. That allows me to center the weight better given my long femurs.
We're going to work our way up to OHS. That is the worst since I dont' have "hypermobile" shoulders like some people do! :-)