This is getting off topic, but by 'riding' the reset do you mean using a lighter trigger release and feel for the click as not to release to far?
Another way to put it: "Riding the reset" is to immediately squeeze the trigger upon feeling or hearing the "click".
I for the life of me can't see how guys double tap 2 shots accurately in 1/2 a second!
I actually think it's a double-edged sword.
A very short and positive reset makes it easy to double-tap extremely quickly, but my experience is that novices tend to jerk or slap the trigger too quickly upon feeling the reset, or worse yet, some may unintentionally fire a second shot by instinctively clenching their fingers under recoil.
You know those holes in the ceiling at the indoor range? Ever wonder how they got there? Yup, this.
One benefit of the M&P's "terrible" reset is that it's very difficult to accidentally double-tap under stress.