I would say use what works for you, so I don't take it that you're second guessing me. For your shooting style, a SFP may be the answer.

My reasoning is the following:

-MK6 is a 1-6x, but I may not always want to run it at 6x, like if I'm trying to hit something 200-300m away while wobbling around on a barricade.

-I don't always spin a turret when shooting, especially if I'm transitioning between varying distances quickly, so if I'm on something other than 6x (like above), a FFP will allow me to still use my holds, unlike on a SFP. Now, at that range, would it matter? Maybe not sometimes, but I guess it would depend on how small the target is.

-MK6 (and the SWFA and Vortex HD GenII), when you go down to 1x the donut turns into the dot. That's how you're able to get the relatively small RDS-like reticule without all the other junk in your way.

-Lastly, I'm spoiled and I'm able to treat myself with the luxury. A SFP is certainly very capable, but since I could get a FFP, then why not.

That was most of my reasoning, but may not apply to everyone. Long term, I'll be interested to see if it was a smart purchase. If not, I'm sure I could get most of what I paid for it back.