I have both and much prefer the on/off switch of the 2 by a long shot. Yes, you have to remove to replace battery, then recheck zero, but the batteries will easily go 5 years+. I hear a lot of folks complain about the brightness of the dot and starburst. Cut a tiny square of electrical tape, cover the tiny light sensor on the front of the sight where the edge of the tape barely covers it, then slide the tape until you get the brightness you want. That clears up the dot.
The FF3's on/off mech is a PITA in the field IMO. Also both mine and a buddies don't even come on most of the time if you just hit the button once. You have to be looking thru the sight and hit the button, wait a few seconds, hit it again, wait yadda yadda. Once it's on, it's fine. I do like the fact that it adjust easier, but there's no noticeable clicks and it moves so easy I often wonder if it's actually staying put. At least with the 2 it's locked and done. The battery on top is a better idea, but I don't know about you guys, but it's kind of a pain to change since it's so far fwd.