facts:
1) The hi mount microns will not come up much higher - go call micron yourself...sorry, that is NOT a hi mount. Believe me, I was a faithful micron guy, but sometimes a little change is good.
2) That rumor about breaking in your bike with a stock pipe is bogus. Some people DO prefer to do so, however oftentimes it is because they plan on putting on a full exhaust and want to really feel the difference between stock and full system. With a slip-on the difference in power will be barely noticeable...that is a fact, anyone who knows sportbikes will tell you this is the truth - if it is more power that you want, than shop for a full system. As for break-in, this is a slip-on and you can put it on whenever you want. I would NOT advise this with a full system.
3) On an R1 passenger accomodations are already lacking. But I think my girlfriend put it best...Her quote was: "It's a fucking sportbike! It isn't supposed to be an easy chair - that'swhat Goldwings and Harley dressers are for!!!" Ahhh..my love...all this from my girlfriend who was born in Poland and only speaks English for 2 years....Aga, baby if you're reading this, I love you.
So anyhow, regarding passenger discomfort, first and foremost, see if you retain the passenger peg! Many hi mounts DO let you keep the rearset and peg. Devil is one of them. Since the rearsets and pegs are high anyway, your passengers legs will be higher (knees more bent) so they'll be far enough away from the pipe to not get burned- at least for the most part. This is true for Devil, and also for micron since their hi-mount isn't too high. I don't know abuot MIG, because all my friends that ride with MIG hi pipes have solo tails and hate riding with passengers! Aga will be riding with me on the R1- we sat on one at the dealer when they first arrived and she said "God, it's alot more comfy than your Ducati!"