I bought a Versys 650 a few months ago and can relate to your hesitant feeling.. Over the years I've owned several different bikes and absolutely love the performance of a well-tuned inline 4.
When I first got the Versys I didn't feel an overwhelming joy about the bike, in fact I felt uncomfortable with the bike and did not like the engine. I quickly found that the suspension was setup way too hard for my size and riding style. After fiddling with preload and dampening a few times (made it softer) the bike handles so much better.
Now I've been "eating chicken strips for dinner", if ya know what I mean.. haha! and the bike has definitely started to grow on me. Ultimately on an open piece of road the horsepower from an inline 4 cannot be matched, but 'within city limits' the consistent torque of a parallel twin has really fun potential.
Adjust the suspension to met your needs first and foremost. Once you're comfortable with pushing the bike, you'll find the low-end torque really digs into the road and is great fun thru quick corners.
I also find the low end power to be great in traffic.
2008 Versys 650
Been riding 8 or 9 years, and have owned 8 or 9 bikes; its an addiction I can't quit...