jhw - if you want a sportsbike then get as modern a 600cc as you can afford, they got progressively more peaky as they evolved, to the point that most of them now have the rev limit somewhere between 14,000rpm - 16,000rpm and the power doesnt really kick in until north of 10,000 revs....the relative lack of squirt in the lower revs is ideal for somebody new to sportsbikes. It means you wont loop it by grabbing too much throttle, you wont spin the rear end up pulling out of junctions etc....all things that can and do happen to newbies on big bikes.
Dont get an Aprilia 250, lovely as they are they are a money pit as the 2-stroke engine requires more than a little TLC to keep them sweet....dont get a twin, they deliver their power in great huge dollops lower in the revs and you will probably end up flicking yourself off the back if you're clumsy with the throttle...and you will be to begin with.
I got a Kawasaki zx7r for my first bike, a 750cc 90's World Superbike legend....to say it was too much is an understatement, the learning curve was steep and after 3 months i (predictably) crashed it opening up the throttle before the bend i was on had opened up properly, bike was still leaned over and the rear span up....couldnt catch it in time and smashed the bike into the kerb and then a wall....thankfully i had parted company with the bike at this point and was sliding down the road....wounded pride and all that.
I then did the sensible thing and went and got a sports 600cc for the reasons i outlined at the start of my post, much better and spent a very enjoyable 18 months on that bike learning the nuances of bike control until i sold it on and was ready for something bigger again.
