Some more points in the SOT vs. Sit In discussion:

You will stay much dryer in a SI than on a SOT. I took this into consideration when I got mine. I like to get out in the early spring and late fall, and while I live in KY where it does not get real cold, I have become somewhat of a wuss in my old age.

A paddler in a SI presents much less "sail area" to a steady wind than one on a SOT, as the second sits much higher than the SI. Now for flyfishing this becomes a bit of a challenge as the extra height of the SOT would be an advantage in casting.