I like mine. They are fairly smooth and don't smoke bad at all. They can get warm but I am running a stock charger for now, so I'm not suprised.
I have only towed about 7K with mine so far. They don't have the low end that the EDMs have (I ran a set of jammer 4s for a while) but my cruise control is also a lot nicer with the mentals. It could get jerky with the edms as the truck was adjusting the throttle lightly under cruise control. That is gone now with the mentals. I know its because they aren't as efficient and responsive as the EDMs but hey, they sure run smooth.
I think they fit me the best of any injector I have run yet (stock, DDIIs, Jammer 4s and supermentals).
I have been running mine with only a boost fooler so far.
You'll make more power and get better mileage with some good EDMS, but all in all, I really like the supermentals and don't plan to get rid of these until i have to. Just my $. 02
Jason