I have the ff3. Bought it used off the EE for quite a deal. Too good in fact, as after 3 shots on the sks the battery cover flew off. Turned out the threads on the battery cover were stripped.
Sent it to Burris in Colorado in early June. I received a brand new unit 2 days ago. I've mounted it but haven't fired (yes I'm dying to get to the range).
Therefore, two things I can say about the FF3 is:
1) I'm impressed by the Burris warranty. I would buy from them again just based on them upholding their lifetime transferable warranty on what was likely user error damage.
2) DONT OVER TIGHTEN the battery compartment. (kinda goes along with read the instructions...)