This month's Sport Compact Car has a good article comparing the Stock S2K to a CT SCed S2K to a Spoon Racing S2K. That has a lot of info that I found VERY useful.
The article bears what the HP chart shows -- the car is faster but the blower makes great HP gains as RPMs increase. VTEC must be heaven.
I don't think you'll beat a new M3. He has the low-end torque to beat out a S2K in a 0-60 drag. Maybe if you do a clutch drop in VTEC, it'd be pretty close!
The results look like about 1 sec off 0-60. Not exactly but close. That is pretty respectable! Remember the additional stress you will be putting on your drivetrain, though.
Good luck with your decision

 

I have had my Comptech S/C in for a week and I love it. The car just moves out as the RPMs increase. I had the local Comptech specialists install it so I can't comment on the install. They had it done in one day. I have had the good luck of driving a lot of great sport cars over that last 30 years and with the mods to the S2K I plan on keeping this one in my collection. Plus it is the one I choose to drive daily because I enjoy it so much. I visited Comptech in Sacramento about 2 months ago before the upgrades and I was impressed with the whole operation. They even called the local install tech the day he was doing the install to check if he was having any problems. A very nice touch.