Ok. I'll throw in my
I rode dirtbikes in high school. I rode them hard and with a bunch of guys who went on to race MX in both amateur circuits and professionally. I had good teachers and learned a lot of good lessons for dirtbike riding.
That being said, those lessons have helped me with only two aspects of riding my new CBR600F4i: shifting and saving my bum when I'm about to go down.
Cornering, braking, keeping power on the back wheel, throttle/engine speed management, proper shift points, traffic safety and strategies... all of these I've had to learn from scratch, either from books like
Proficient Motorcycling or from my MSF instructors.
Now, I'm 25 years old, and I've seen friends die on sportsbikes. I'm not so immature as to think "that can't happen to me". In all seriousness, it quite likely may. An accident that would have merely been a sore chest and/or broken wrist in a car would probably kill or leave maimed for life a motorcyclist. The acknowledgement of that fact tends to give a person a lot of respect for the he or she is riding, regardless of the number of CCs the engine weighs in at.
So, my advice is, buy whatever bike you feel comfortable taking the responsibility for, because when you get on that bike, no one other than you are responsible for your safety. If you ride it sanely for the first month or so, then start to get overconfident with the bike, that can kill you just as quick as a newbie mistake your first day out on the road.
RIDE WITHIN YOUR ABILITIES.
A 250cc sportsbike will allow you to exceed your riding abilities, just like a 600cc or 1000cc supersport will. The only difference is the SPEED at which such mistakes will happen, the utter velocity at which factors will accumulate and lead to an accident. If you slip on the throttle and accidentally torque the c r a p out of it on a 250cc Ninja, you'll jump from 40mph to 50-60 pretty quick, and it'll scare ya. On my F4i, if I hit a bump in the road (like I did my first week) and accidentally lean on the throttle, I will go from 40-80 in the space of time it takes to realize what happened. The bike is simply that much less forgiving. It is VERY easy on my F4i, which is arguably the tamest of the sportsbikes you could buy in the 600cc class, to override your abilities.
So, I will repeat what I said above, and pray that it sinks in:
When choosing a ride, make sure to choose one on which you are comfortable assuming responsibility for your own safety.
So long as you follow that advice, I have no doubt you'll be ok. Ride safely first and foremost, and remember that reducing the risks doesn't end when you choose a bike that fits you.
Oh yeah oh yeah its your birthday its, its Christmas, its Hanukah, its Quanza..Uhhhemm.. Sorry. 
I completely agree that when I read someone recommending a bike like this over newer, better performing bikes I really have to laugh. Kids these days don't realize how good they have got it.....
That R1 will lift up 1-3 with out even breaking a sweat and if you have big enough cahonies you can do it in 4th... And that R1 would leave that Hawk at a stop light w/out even so much as a good by hug...You friend needs to chiggetty check himself and his new R1..
