We spend a lot of time in our TI and I agree with nothing else the TI seats get very uncomfortable after a couple hrs. What I did is cut a 1 1/2 inch foam pool matress and put it in a mesh bag under the regular seat. I am now quite comfortable even after many hrs out at sea. I also hear those I-comfort seats Hobie sells are quite comfortable.
You will find the TI kayak is way faster and more maneuverable than the pa, plus there is not a lot of difference in the weight ( kayak only). Actually the TI is the fastest kayak that Hobie makes, and has way more storage. We have done quite a few rivers and lakes in Colorado with our TI, and have even done class 2 rapids out there. This is just my opinion of course, but I regard the pa to be the ultimate fishing machine, but have never heard of anyone using it for anything else.
Hope this helps