I use a Canon EC-S type screen. its a special matte screen with no split or micro prisms, but its made for precise manual focus with canon's f/1.2 primes. its an amazing screen to use if you dont shoot lenses smaller than F4 on a regular basis (it gets abit dark). so i just need to compose, look at the point i want in focus, focus, and shoot. i don't get 100% keepers, but about 90-95% on static shots and 50% on moving. i've also been shooting manual for 3-4 years now, and the only AF lens i have now is a tokina 17/3.5 so i guess experience helps alot =)
that said, shooting a whole event in MF is not something i would normaly do. in this case, i was asked to shoot a photobooth, and these were candids on the side so it was all 'safe'. honestly though, i was shooting iso 4500/6400, f/1.4 and 1/125, i doubt the AF tracking would have kept up.
Thanks for sharing Ben!