Yeah, I have both, and a variety of sizes..
In my mind, I make a half hearted attempt to keep the bike to the minimum for the ride. By that, I mean my ride to my office doesn't require going over 45mph, with most of it at 40 and less, so I'll ride my 50 scooter.
From there (and I'm generalizing here) I ride what I can get away with.
I ride because I love to ride, and I really don't like driving.. I don't pretend to do it to save money because I think nothing of riding for an extra hour just for fun. I'm not pretending it to be green, because only one motorcycle has a catalytic converter and one of them is a two stroke.
And it's not about being a cheap mode of transportation because I title and insure 7 bikes.
But I do like riding something out of the ordinary, and the scooter falls into that place. I'm 48 years old, 6' tall and 250 pounds and think nothing of jumping on my 250 Honda Helix and putting 500 miles on it during a weekend, riding to a BMW or Moto Guzzi Rally a few hours from home.. That includes the ride and bringing along all my camping gear... And yeah, I smile when I get asked if I really rode a scooter from IL to a rally in Michigan or Minnesota.
We all ride for different reasons.. I ride whatever I think will make me smile the most.