I switched to DSM a couple years ago when it first came out, using it in my M8. Other than the couple issues regarding low BEC current using high end servos and the QC2, I have not had any major issues. Only on rare occasion I get a small "glitch" at the indoor asphalt track I race at, and it seems to only happen one or two laps out of the whole night.
I now have the M11 with the pro version, but am still using the original non-pro receiver in my current touring car. The day I switched from the M8 with standard DSM to the M11 with Pro-DSM, I noticed a difference whether it was reaction speed or not. It seemed to respond a bit faster, or just had more steering. At any rate, I am satisfied with the equipments performace. Even if there is a delay, I have become accustomed to it, so it doesn't bother me at all. I run with all the top drivers, and I am always on pace.