For me it's very similar. I was expecting it to feel very heavy and UN-chuckable in comparison, but it really isn't. A smidgen taller (maybe about an inch?) But there's not a massive difference between them. The thou is just sweeter to ride, much smoother, more torquey and obviously quicker.
Because of the extra torque, you don't need to work the box so much for overtaking etc, which was my main gripe with the 600 - so it's been a very wise move for me.
Not so wise was the 200 mile ride out - feeling it in my bones a bit now