Ive been riding since the mid 70's, been up and down the cc scale many times.
There is no such thing in my world as a Starter bike, Ive never owned one.
Riding careers are generally short on the street , cause people get run over. This has to do with dveloped experience, skill and tactics.
If you don't develop those, all is for not, and will not matter what you ride, and the desire probably wont last.
Sport bikes, no matter how fast you ride them, you get very little exercise. IMO, the reason that you ride has to be understood. That's going to have great impact on the type of bike that you like most.
I mean put me on a crusier , and I'd probably stop riding.
I have a sport bike, but its for covering a lot of ground quickly, not my fun nest bike for fun and exercise. or the one I yearn to ride usually.
How bout a DRZ 400 super motard