The big question is, what size fish do you normally encounter, and second, what size flies do you regularly fish? Also, do you usually fish still waters (i.e. ponds, lakes) or moving water, and if the latter, what kind of currents do you fish in? Those are important questions to consider when choosing the most useful rod, such as you are attempting to do.
FWIW, the T3 is a very nice rod; I got to fish it earlier this Summer when I was out on the Kennebec. I can recall being impressed by the smoothness of the cast. The XP is a faster rod and favors a faster casting stroke. You might try a Sage SLT if you're looking for something "high-end" that's near the action of the T3. Thomas and Thomas makes some very nice rods with a similar action under their Helix line. Alternately, if you want a quick rod with a medium-fast action, the St. Croix Legend Ultra rods are nice. I have an 8' 3-wt. rod that can easily fish 3-, 4-, and 5-wt. lines. It's really a pleasure to fish in waters where the current allows landing fish up to 18" safely. Any higher than that and I switch to my 10' 5-wt. Horizon.