In reply to Jerry67:
I'll weigh in on this one.
some good points so far.
Yes shaft drives can be more economical on the maintenance side but normally fitted on bigger bikes.
Bigger bikes aren't always better, but neither are smaller ones. It depends how and where you want to ride.
An off road/enduro/adventure bike will have a more upright seating position that is better for the back, wrists and shoulders but get a lot of wind blast.
You can bike up a cb/cbf500 cheap as chips or a hornet or an er6 f or otherwise. Hyosung did a 650 twin road bike that is nice but be sure to look at ones made after 2004 as there were quality issues before that.
If you think you can get away with a small bike don't discount Chinese one *prepares to get flamed for that comment* but I had one, it was cheap and hard as nails.
Bikes are a totally personal choice, you need to test ride a few and be prepared to sell the first one you get once you figure out you want something different.
I used to commute year round on a bike, and still would if i didn't have a company car, and i ride a cbf500 its not the most fun bike in the world but its dressed up for touring and has never missed a beat.