I have an 2005 C50, and My wife has a 2006 Aero, so I'll offer my 1/50 of a dollar --
The C50 is heavier than the Aero. Neither is a real chore to move around in the parking lot, but the weight difference is noticeable. But, the Aero is no more prone to being blown around than the C50. Both handle very well, no bad habits and predictable steering.
The C50 has fuel injection, the Aero has a carburetor. The Aero starts just as easy as the C50, but in true Honda tradition is a bit cold blooded; give it a couple miles before you put the choke all the way in.
I think the C50 makes a little more power; it definitely accelerates better. But, the power delivery and transmission on the Aero are just a tad better than the C50. On the other hand, the Aero delivers about 5-8 more MPG (even better when my wife is driving)
Brakes work about the same on both.
I like the 2 into 1 exhaust on the Aero better -- gives a wider range of choices for saddle bags that won't end up with a hole burned in the bottom. We just ordered a
set of these saddle bags for the Aero, with the quick detach kit. I'll post pics when we get them mounted. The only 2 into 1 exhaust I've seen for the C50 are the jardines, and I'd like to hear them before I buy.
My wife bought her bike late last year because she had an opportunity to sit on both an '06 and and '07 Aero. The handle bars on the '07 are wider and more like the C50. She like the ergonomics on the '06 better (that, and the fact that it is in a dark brown / black color scheme), so she bought it while she could.
The floorboards on the C50 are a definite plus. Both seats are pretty good for stock equipment. I
added a driver's backrest to mine, but even without I've done 300 mile days without trouble. At first, the seat on the Aero seemed lame, but it stays with you during the ride, and my wife can sit in it all day.
We both have Memphis fats windshields, and
a set of chrome air deflectors.
Both are really good bikes, and if I was in the market today it would be a tough call.
