I figured I'd ad my impression in this thread if that is alright , as it probably isn't worth a new thread.
For starters, mine isn't a comparison as I don't have anything else to compare to, but an impression of a bone stock bike with Ivans reflash and no other mods.
Quick review: the bike runs like a champ. One word..... Smooth
The first thing I noticed within seconds of riding is compression braking is now what I consider normal for an inline four. In fact my first stop sign it surprised me a hair as I needed to actually use my brakes instead of the engine doing most of the work. I had adapted easily to the extreme compression braking while stock, but really like it this way much better.
I'm not sure if I feel any of the (minor) HP/Torque increase but the fueling is so smooth now the impression is it pulls easier/harder.
Now, the snatchy throttle thing. A disclaimer here, as for me personally it wasn't a huge problem. Did I notice it? YES. Most annoying at lean angle while opening from closed throttle. For the most part though it didn't bother me as much as some, so I didn't have as big of a problem to fix. But yeah, it's gone. I guess the best testament is when I was riding hard I didn't notice anything. I spent some time trying to make it do something bad, going from zero throttle, cracking it open in a ridiculously slow manner. Maybe I felt something, or not, but now that is honestly holding it to a higher standard then any bike. In short, for me, problem solved.
Over all I got what I expected. Not any huge power gains, but everything, everywhere just smoother. The bike feels more fluid now. This mod took a bike I've been falling in love with over a few months now and just made it better.