A recent German magazine published tests of the AF accuracy of the current crop of DSLRs (OT - but they are likely to be at least as accurate as an F4, hopfully some progress has been made in AF since c. 1988), using many different lenses,focusing distances, subject types, etc. Different results according to brand: Canon was worst, with only something like 30% perfectly in focus, 20% acceptably in focus and 50% out of focus (going from memory here). Nikon did better with about 50% in focus.
This fits my own (fairly extensive) experience of AF usually not being as accurate as manual focus (at least with a decent viewfinder).
I'll get hold of of a copy the magazine sometime soon (I quickly read the test in a library): it really was interesting.
But if you find 100% perfect focus using the focus indicator light, then YMMV (and your quality standards too)...