I have used EOS3 for a half year and here are my comments:
AF speed - faster than EOS 1N and EOS5, of couse all focusing point are active
Film transport - fast, but you need a heavy Booster E2
Focusing screen - brighter than 1N but not 5
If you are currently 1N user, you can utilise it in a short moment and the price is now very attractive (less than USD1000 in grey market) and the booster E1 (for 1N, 1...) can be used but the function is limited.
In my experience, I only use one (mostly centre) foucsing point to improve the efficiency. Of course, the AF speed is superior than EOS1n, 1, 5 .... , excpet 1v.
Consider the price and performance ration, I still choose EOS3, and do not choose EOS1v.
Comments are all welcomed.
Hong Kong, China