If it's doing well with Final Cut Pro X, it should also do well with Pro Tools. Video is certainly quite demanding! How fast does it render?
As long as I don't use Compressor and render straight from FCPX, the times are pretty quick. I was rendering 5 minute training videos (mv4 for distribution on our internal website at work) and the total time was 17 minutes per video. I was also watching Season 15 on South Park on Netflix at the same time.
Pro Tools should scream on it. I need to install PT on that computer. I've have been able to edit the audio pretty well in Garageband and then kick it back over to FCPX, but everyone I work with knows proper mic technique and is used to doing voiceover work. PT10 would come in handy when I eventually have to use an inexperienced person.
I have PT and FCPX on my iMac at home, and PT is nowhere near the resource hog that FCPX is, so you should be happy with the performance you get out of that machine. I'm still running the last version of LE, but I can't imagine PT10 being that much more of strain.