Burris FastFire 2 & 3

[Mobuck]

After having looked closely at both of these and now have one of each, I see a glaring error in my logic. I mounted the FF3 on the rail of one pistol and the FF2 on a Burris rear sight dovetail on the other.
Just for information purposes, this was bass-ackwards. The FF2 requires removing the sight from the base for changing the battery. When you do this on the dovetail mount, everything comes apart requiring a complete start over with zeroing.
It's mounted so I'll run both as is until the FF2 battery gets weak and then do a complete swap. Putting the FF2 on the rail base(changing the battery is less likely to seriously affect zero since the base stays locked on the rail) and the FF3 on the dovetail base(changing the battery won't affect zero).
FWIW
I don't see any real reason to buy a FF2 since the current cost is equal to FF3 and the battery change thing is a fairly significant disadvantage. I bought the FF2 at 1/2 the price of the FF3 so seemed a logical compromise.

 

[huntsman22]

I don't see any real reason to buy a FF2 since the current cost is equal to FF3 and the battery change thing is a fairly significant disadvantage.

The reason I like the II is the simple on/off switch and a cover that you can pop off and stick in yer t-shirt pocket. The obnoxious cover and multi-push button switch on the III are a bigger PITA than checking zero after a change.Batteries last a long time and I never found it hard to re-zero, as it gives me another excuse to shoot more......

 

[Mobuck]

"I never found it hard to re-zero,"

Time will tell on this part. Definitely appears that having the unit completely apart with nothing left intact to give some help with relocating the sight in the same exact location will make any chance of even being close to returning to the previous zero "extremely problematic"(OK--impossible).
This is the impetus to swap the units between pistols-so I can change the battery w/o having to do a complete re-zero. The rail mount base can stay in place and the 4 pins and 2 tapered head screws should return the FF2 to nearly perfect alignment.