I have several E1 3-9x40. I have no experience with the FF II but really like the E1. As per Burris, because I asked, the E1 is basically a FF II with etched reticles, better turrets, and a difference magnification method ( ring vs turning whole occular). A buddy knocked my Kmber MT with E1 on to the pavement last deer season. It put a good ding in the vertical cap but didn't move zero. I'll say I've replaced several Leup VX3 with E1s. I found a deal on E1 with the Plex reticle. I scooped up 3 of them.
I've also been testing scopes and the E1 is every bit as good as a VX3 with respect to seeing dark targets at the ends of daylight. The last 2 to blink out to my eyes are the VX-3 and E1. I dig them.
That's good to hear - I've also been replacing a lot of scopes and have been buying up the discontinued Burris C4 3-9x40's (8 of them so far). I've assumed they they were similar to the FFII and the same as the E1 with a different etched reticle. I've been really liking these scopes...