The whole lens/body autofocus topic has driven photographers crazy for years. The only thing that saved my sanity was the purchase of a 5D3 last year. All my old lenses that drove me crazy on my 5D classic, now work perfectly. Some need a little MFA, but not much. Even my Sigma 50/1.4 works like a champ.
I can see why Canon doesn't put MFA on the Rebel bodies - most users mount zoom lenses with fairly small apertures, so focus errors are masked by the DOF. Although i do recall adjusting the focus on my 450D with a teeny tiny Allen wrench one time in order to make it work with my old 50/1.8