do it... great learner. I do however want a new bike now, but nothing against the SVS. Just i wanted a proper sportbike, settled for the SVS as a learner, and am ready to move on. It is very, very fun and I highly reccommend it.
However, I would place the Ninja 250, 500, CB-400 (CB-1), Bandit 400, FZR400, or most any enduro over the SV.
The SV has a lot of engine braking, and a snatchy/sensitive throttle that can be really difficult for a person who isn't familiar with the motor skills to control it. Also, the SV is still expensive to drop, with damages typically ranging from $400 to $1,600 if you can't live with dings and scratches.
Also, the performance envelop on the SV is pretty high up there, which makes it hard to push yourself with. I often ride my CB350 and my SV back to back, and the subtleties and finese of riding are far more pronounced on the CB350, with its soft frame and flacid suspension.
If your friend wants to improve as fast as he can, and become the best rider that he can, he should get a 250 - 400cc four-stroke enduro, and put in equal amounts of time in the dirt/twisties/city to really gain the important skills to becoming a good rider as fast as he/she can.