I'll offer my opinion as I have experience with both rods. My experience is that the BIIx will be lighter in hand and very capable, a delightful rod but more of a "trouty" 8wt- not quite as capable in the 8wt realm as the T3. It's a fine rod for most things that involve a floating line but if you want to cast sinking heads, big deerhair bugs or very weighted sculpins, I'd opt for the T3.

About 18 months ago, a buddy that works at an Orvis dealer got us all together for an 8wt shootout including the BIIx, T3, Scott S3,( and something else that I can't recall). I could have lived with any of them. The T3 seemed to be the more powerful of the bunch and would have been my choice for saltwater fishing.