I’ own an FF 2 and 3. The 3 is the better unit. Smaller 3 minute dot and lets you choose auto brightness plus high med and low. I’ve never needed to run it on anything other than auto but it’s personal pref for sure. I’ve not owned a vortex but it has more range of adjustment but no auto function. I suspect that any of them will serve you well. The FF2 is auto brightness only and a 4 min dot. My only complaint with the 2 is that it has locking screws for the elevation and windage adjustments. You loosen the 2 screws, adjust zero and then lock them back down. I found that the act of locking them down can change your poi slightly. The solution is to only loosen the lock screws just enough to move the dot. Then gently tighten a bit but don’t turn them down hard. Bit of a pain in the rear. Neither ever cost me a bird.
Lots of choices out there now at a big spread in price. Absolutely nothing wrong with the Burris. They are bulletproof and I wish I could add up how many turkeys Ive killed with mine. Just in the interest of tinkering I bought a Holosun 507c this year and a SwampFox. Both of those have the dot surrounded by a larger circle and I thought it might be faster for target acquisition plus I wanted to try green light vs red. Both of these are excellent so far on pattern board. Will see how they hunt. Both of these brands use the Trijicon RMR footprint. The Burris and Vortex share the same Burris footprint. Sumtoy has bases for both.
If economy doesn’t matter the Trijicon SRO is absolutely the nicest I ever looked thru. Crazy clear glass and a perfect little dot.