In the RMRcc: Which dot size do you recommend for carry: the 3.25 or 6.5?

Either will do fine. Whichever is cheaper ...

3.25 is what I go with.

I’ve only got a RMR Type 1 and I find the 3.25 ok for distance, but I’m wanting to try the 6.5 for up close.

I have two RM06s (3.25) and two RM07s (6.5). Either will do fine, but I much prefer the smaller dot.

3.25. With my astigmatism, I can't imagine trying to shoot the 6.5. it must take up the entire window...

I’ve carried both the 3.25 and 6.5 moa RMRs on duty pistols.  2.5 years on the 3.25 and one year on the 6.5 moa model.  I have seen zero advantage to the 6.5 moa.  It’s not any faster, it’s not any more bright or visible.  On the flip side, the 3.25 can get more precise when you want precision at the range.  For carry, cranking up the rheostat higher for the reticle will make it about the same perceptible size as a 6.5 model because of the reticle flare.  I’ve also run a 3.5moa Aimpoint ACRO, and have time on other optics like Holosun, Leupold and Sig.  3.25 or 3.5moa is more than enough and I think overall more advantageous, and I’ve never gleaned any advantage with a larger reticle.  Just my $0.02