I always use the inside rack if I'm the first bike on it. It's just easier to wheel the bike, on my right side, out into the street, drop the rack with my left hand then lift the bike and 180 it into the inside rack. That's the way most racks 'round here are oriented anyways.

I've only had one Portland transit driver complain about having a single on the inside. Dunno how he'd manage when the rack's full then the outside bike passenger disembarks first. Probably cries the whole way.

One tip. Find the balance point on your top tube. Get used to grabbing it there with one hand and using your other hand on the handlebar to guide the front wheel in. My road bike's balance point is right above the BB. A bit farther forward on the rigid-forked MTBs. Even farther forward than that when I have a suspension fork on 'em.