A first for us...we rode 2 up the other day, and decided to try it on the MP3. Overall, the scooter handled it well; me...not as much. I could definitely feel the extra weight on the back (I didn't increase the load on the shocks...didn't occur to me until afterward) and the needed increased stopping distance bothered me a bit. I had a couple of moments of chanting "please don't change, please don't change" under my breath while approaching stoplights.

I also had this irrational fear the Spouse Thingy was going to fly off the back of the scooter. Not sure where that came from.

I think most of my discomfort came from the unfamiliarity of riding 2 up and I can get over that with practice (presuming he'll be willing to ride as my passenger again.) I did have a little bit of trouble making right turns with him on the back--going wide--where I normally don't, and after backing out of a parking space I nearly dumped the scooter when the front wheels unlocked. The parking lot surface was not completely level, with the wheels suddenly unlocked the balance shifted, and I had to work to keep it from going over.

He complained that there's not enough space for the passenger's feet; he has size 9 shoes and the footrests look like they're made for someone with toddler size 3 feet. I didn't appreciate that much, either, since his feet kept jabbing into my calves, leaving some nice bruises. The seat seemed all right for 2 up; the grab bar is a nice touch, and while I felt like I was too far forward, I think that was because I didn't want to sit too far back. The whole him flying off and all...

(And if none of this makes sense, it's 3 a.m. and I can't sleep...)