Just doing some research for a new set of brakes and noticed you'd tried the ROR and Cura 2 pots. I got onto Formulas back when The One's were released, had two sets of them, then a set of R0's, and also a set of RX0's (seem to be a hybrid of RX lever and R0 caliper, they are super grabby).
I've been running 9020 XTR which we inconsistent and lacked power in steep trails, now trying some Hope E4's but I'm not getting on with the lever shape with the big hook on the end and they seem to pump up even after several bleeds.
I'm looking at other options and the Cura have caught my eye, just wondering how the Cura 2 pot compares to the ROR? You mentioned the Cura is the natural evolution of the ROR, are they better in all regards? Both can be found for a great price at the moment.
Also did you ever try the Cura 4 pot? The seems to be very few reviews around on them.
Thanks for the great reviews!