So, I did the rolling technique today. A couple of things I learned-
1) My back feels completely fine if I do it, and all supposed flexibility issues disappeared when I had an actual bar to hold onto to let me sit back more.
2) I could feel my hamstrings and glutes a whole lot more. Previously, I wouldn't feel them until I went up to 300+. Now, I felt them when I pulled 135. The weight came up significantly faster too, so I assume that I had more muscles working.
3) It's hard to get the weight onto the heels. I've always pulled with the weight distributed more to the outsides of the feet than the heels, and the sensation is obviously different.
4) My hamstrings and glutes are really weak. I felt my hamstrings and glutes working up to 255, whereupon I didn't feel them at all when I pulled. Even when I did the rolling, I think I subconsciously just prevented myself from using my posterior chain because it's simply not strong enough to handle it. Now I have no idea what muscles I was using to pull the weight up when I did 315+, seeing as how my posterior chain apparently isn't a major part of it (T3hpwnisher's comment comes to mind).
I think I'm going to completely reset my deadlifts and do them a whole lot more frequently. Instead of the assistance lifts I've been doing (good mornings and rdl), I'll just do squats and deadlifts 3x, with the deadlift more to feel the muscles and get them activated and learn the form better while the squat is the major strength builder.
Is this a good idea?