I focus, recompose all the time and it works good for me. H2F with CF backs. I use the 100 quite often also open. I have started using the 210 at close range pretty often as well and use it at 4.0 most of the time. No errors there with focus/recompose. Yes, focus is brutal with these things. Be off just a little and you wish you would have brought your tiny D300
If only MF had the AF systems of 35mm equipment, sigh........