I'll drop in a first hand report FWIW. I was out for about 25 years and jumped back in with a full upgrade. This meant I had a new car and M12 to break in, (or just break to start with), and a vintage car with an old 27 Mhz radio to compare it with.
My old car drove comfortably and predictably for me. I'm not good enough to worry about shaving inches but things went pretty much where I wanted them.
My new set up had a tragic encounter with a board on the shake down cruise and left me with a well hidden cracked front upright leaving me to chase steering problems along with everything else usually found during break in. I therefore got very involved in learning all the trims, adjustments, rates, curves, and setting available on the M12.
Compared to my old radio, it was much easier to change dual rates, (huge difference), response curves, (assigned to one of the many new trims), and directly related to this thread, the Feel setting. Feel allows you to choose the latency to suit your needs, (also easily assigned to a trim dial), over a range of +/- 5, default being +5. For comparison, the mid setting is suppose to give you the same response of the M11X, ( see pg 69 of the manual.)
From what I could tell before and after finding and fixing broke car parts, the Feel function is probably the least responsible for the overall performance of the car. For what ever setting I chose, modifying dual rates, response curves, and balances of brake trims would overwhelm the fine tuning of changing the Feel.
The M12 really is a modern marvel. It will let you mix up any brew you like and serve it back in half a dozen flavors at the touch of a button. If you're good enough to make a living racing little toy cars, then the latency functions might give you an extra .1 and give an edge to move up a rung or two on the ladder. Joe Lunchbox will have a cool new toy to play with in addition to the hundred or so other adjustments he has available to try and work his way out of the B main at the next club race. Clipping a board at speed will cancel out all of the advantages the electronics can give you.