I have run Digidesign Digitranslator 2 on an Apple G5 desktop computer running Pro Tools HD. I can't say that I ever encountered any problems related to performance within this configuration, and also never heard of anyone else having any problems running it. Digitranslator 2 also isn't the type of software that I would run everyday - I've only used it two or three times when the need presented itself. I guess that some users will be using this on a daily basis, I have only used it a few times.
Digidesign Digitranslator 2 isn't the type of software that I can really recommend one way or the other. If you need it, you need it and if you don't then you don't. However, I will say that the software is programmed smartly and is very easy to use. It gets the job done in situations where it is really the only piece of software that could do the job for Pro Tools users! While Digidesign is no more and is now fully under the name Avid, the Digitranslator 2 won't be affected by this at all as the same support is still available. If you find yourself needing to switch between Pro Tools and other sequencers more often than not, having this around will be a major help. I don't know anything about what the Digitranslator 2 costs, but judging by the fact that Avid/Digidesign usually overcharges for necessary piece of software like this, I'd recommend only getting it if you really have a need, which of course is a no brainer as you wouldn't be looking at this if you didn't!