The question is what is the difference between the 91 tune and the 94 tune. If it is 2-4 degrees of timing advance and 2-3 psi of boost, then it would be worth it, assuming you're willing to run 94 octane (presumably from Sunoco/Petro Canada) and you have the proper supporting mods to take advantage of the tune (see below).
Do you have an FMIC and/or water/meth injection? If not, then I would guess that your intake air temperatures are going to limit your peak performance (meaning that you'll never be able to actually benefit from the potential performance of the 94 tune, particularly if you're still on the stock turbo in your 2.5T).
If you have the ability to datalog, what temperatures are you seeing for intake air temperature (above ambient) on sustained WOT runs?
I realize that the exclusivity of this section of the form limits me to little more than browsing but I also was fairly confident this is the only place I would receive a concise answer. My intake temps are not ideal and will remain that way until the supporting mods can be completed (post daycare freedom) so its the usual story of hardware before software here as well. Good to know, thanks soupandspoons