scottmisfits- I have only ran the motor with the 2035. It does everything well with that pipe so I haven't felt the need to try and find anything else to run.

Joey- not quite sure how to comment because I am honestly not sure if the motor I am running will be the full on production released version, but from my experience thus far, the power band is a little different but the overall characteristics are similar in that OS engines are known to tune well for novice and pros alike. I have put about 3 gallons through the engine, and it's always been an hour on HSN or LSN from a great tune. The carb doesn't jump around alot which is what OS had a good rep for. One thing I have noticed and confirmed with BT that it was normal was the motor will run a little warmer than a Vspec at optimal power, most people run Vspecs around 220 from what I have seen, and my 121 likes to be around 250-255.

As far as power, the motor is very deceiving, as in it's a smooth motor so at first you think the bottom end is soft, but then you easily clear jumps that you thought may be more difficult. The std vspec may have a little harder hitting bottom but the 121 is a pleasure to drive.