no problems that I have read in the past 1 1/2 I have been reading the forums. The only problems that people have had was when they were adding too much hp and tq with programmers. The allison is a pretty strong transmission. As long as you keep the programming under 100 hp and aren't at WOT when you shift to 5th, you will be fine.
That's a kind of opinionated I think. I know the Dodge isn't, but I know that the Torqshifts are very good from what i've been told by people who have them, as well as what i've read. Although I haven't read or heard as much on the Allisons, I know that they're good. But I can't say the Allison or the Torqshifts are better than one or the other.