Very impressive - as everyone says above. Increase in pre spool-up responsiveness is impressive. My expirience differs from most other comments in two ways:
1- Did not lower my EGT's.
I have a 2 mile, 4% grade I use for testing. Got exact same readings as without EZ. Only tested on #3, #4, #5; from 60 mph to 100 mph at WOT. I hit 1350* on #3, and can tickle 1500* (with a B1-2 turbo) on #5 about the time I hit 100 mph. Admittedly I must have some other problem due to the fact that I have always had higher EGT readings than others with same power options (Even before B-1, with EZ and DD2's I hit 1200*). With present set up, I can cruise on #9 all day long and do anything I want under 3/4 throttle. But WOT gets very hot, very fast!

2- Did NOT get a lot more smoke! Left EZ on middle setting. I'm using EZ for timing not fueling...TST has plenty of that for what I want. And as I understand it, the timing is the same no matter which EZ responsiveness setting is use.

Will definately leave them stacked - excellent increase in low rpm drivability with no downside I can see!

RJ