It depends on how well they balance them for me. 2hrs in XI were extremely unbalanced. some were amazing others were horrible. and some down right pointless.

Take ranger for example Eagle eye shot was extremely weak compared to Barrage which only had a 5min timer.
Then you have Nin's 2hr. which was just sad. Used as a free warp more then anything.
I can go go on but i think you get the point.