Keep in mind now that you’re moving into faster & longer lenses (the 50mm becomes an 80mm on the 7D, 60D & T2i) focus is going to get harder and harder to maintain throughout a shot. You’ll find quickly the necessity for a follow focus unit, and with that whenever you can afford it a focus puller. The real downfall to the 1.8, besides build quality, is the focus ring, which is very thin and doesn’t really allow for a lens gear to surround it. The lens gear is what a follow focus unit requires to operate. Meanwhile, the 1.4 has a much wider focus ring that perfectly accommodates a lens gear. It’s still going to be a challenge given the very short focal throw of any still lens, but a geared lens with a follow focus will bring you much closer to pulling it off.