Only thing I notice is power levels at 40-80 is higher which is good. Launch won’t make you feel sick or anything. Honestly it’s noticeable but not THAT Noticeable. You sound like your on the verge of buying urban and I’m here to try to stop you from having buyers remorse.
I just went out for a "drive" just now after the boost was applied early this AM.. 80% SOC, 51F, flat roads and man.. you've gotta be half-dead NOT to notice the difference at launch, and especially as you say between 40mph up.. TONS more oomph here.. Of course, not quite P3D levels, but sheesh it feels like 80% of the way there, in spite of the numbers others have reported.. To me, it's the feeling, not just the numbers... This will keep me happy for a good while. I can now feel the blood rush to the back of my 'noggin now on liftoff.. I did about eight or so launches, and now, stuff flies all over the cabin during acceleration!
Prior to the upgrade, the launch off the line felt a little "casual" until you were at speed.. Now, there's more of a rush to it. I need to test it out on the same test route that I used to test a P3D a couple of months ago for a comparison. The P3D felt like "teleporting" in Asteroids, to the other side of the intersection.. I still need to compare that, as I was on an open road to test today. In everyday driving, my wife took it out for an errand, and unknowingly noticed the power just casually around town too. She usually drives in "Chill", but I had it in "Sport", soooo.. "Hey hubby, how come it's so fast now?"
In short, IMHO, the upgrade is TOTALLY WORTH IT, for those that feel stuck with LR AWD, with the desire for more acceleration and not willing to go through the hassle of selling it for a P3D.. (me). ZERO buyers remorse here for this upgrade. My wife even approves..
Of course, for those that haven't pulled the trigger on a Model 3 yet, try to get a Stealth or Performance version.. even more thrills.. Otherwise, this "Acceleration Boost" package is a worthy upgrade, IMHO.