I am 6' and 160. I don't consider myself a "big" guy. I moved up from the 8.1 to the 8.5 this year and it made a HUGE difference in my paddling. The additional volume floats me higher in the water, I'm more maneuverable, it is easier to boof, and I punch holes like no other. I love the extra volume.
If you can get a 2010 model, the addition of the ratchet back-band and the more bulbous nose makes a huge difference.
You ARE a soul, you HAVE a body.