All depends on the rider. The bike will only do what you tell it to, the difference (I've learned) between a good starter bike and a not-so-good starter bike is how willing to do what you tell it the bike is.
For example... cruise along in 3rd gear on an SV650s and "accidentally" whack it to wide open throttle. It burbles happily before starting a strong steady climb in speed and RPM. Cruise along in 3rd gear on a GSX-R600 and "accidentally" whack it to wide open throttle and you better be holding on and leaning forward or it's going to dump you on your bum.
I made the jump from an SV650s after 5 months to my GSX-R600 (that I just got last week, I'm going to go start a thread so you guys can flame me
). I love the bike to death, the power is so silky smooth. But it has surprised me already a few times, but I'm riding it so gingerly trying to be ready for all it's little surprises that the ones it has delivered haven't even ruffled my feathers.
The Gixxer isn't nearly so comfortable as my SV was and I miss that, but I've taken it on an hour and a half cruise (about as far as I'll ever go without resting) so I know it's doable for me. The Gixxer is light, even lighter than the SV was, and turns like a monster. I've already picked up where I left off on the SV and am slowly working on my riding skills.
I agree that moving early to a super sport bike, even a 600, is not for everyone. I had lots more to learn from the SV, I'm just glad I have the self control to continue learning where I left off rather than just become a straight-line-squid.
Of course, that leads to why did I change bikes then? Because I love the sound and the look of the GSX-R's, and after riding one I fell in love with the silky smooth power delivery. I have no problems cruising mine around the city, even though everyone I pass tries to get me to wheelie.
I tell them all the same thing... right now, I only do one trick. It's called... "Sticky side down, shiney side up".