the SV is a great bike, depending on what you're used to. If you get off a Hayabusa on to the SV, then yes, it'll feel underpowered, but as you're a new rider, you won't have any such pre-conceptions........
unless you start listening to your freinds who ride bigger bikes and give you shi'ite for riding a smaller bike
DONT LISTEN TO THEM! More importantly, learn to ride the thing to it's capability. I'll guarantee you run out of ability before it does!
Some people on here will tell you that you need to upgrade the suspension before the SV will handle well. I won't disagree with them, but I'll say that you're probably still a fair way away from needing to do that at this stage, and if and when you do upgrade your suspension, take it to a specialist, and get it done right.
Get it on the track, and then come back here and tell me if you "need" a bigger bike!