Nice!
I can relate to that feeling!
I've been anxiously waiting until my chinese motorcycle arrives (on friday, or saturday)
http://www.roketa.com/product/2628/0/59059.shtml
They have the same model with a 4 stroke 125cc engine!
Very interesting! Performance should be close to the 50cc 2 stroke.
If it was me, I'd get a 75-100cc 4 stroke for the city, and a 125-150cc for the occasional 60MPH short sprint on the highway.
What color did you pick?