Before you get a tuner you need to take other steps! From what I have read on the 7.3 its major choke point are the intake and the exhaust. There have been several articles recently in the diesel mags that go over this point and just like in a gas engine, more air in/out the better the performance. I have a 6.0 F350, I run the hypertek economiser tune, I also installed a 4" turbo back exhaust and still have the cat in the system. truck runs well with the combo. The 6.0 air filter is capable of supporting up to 500 hp, yet many still go aftermarket!
But add a tuner WITHOUT the necessary extras will be a waste of $$. Go to diesel power and diesel world websites, I think they have the article on line, not sure. But dont waste the money without the other improvements, and yes a tuner does wake these things up but they also need basic help to do so.