I have the CaTCHER and love it. Plan on injectors and a turbo upgrade soon. However, if I were you and already had a Comp, I would not switch. I doubt I would add a special catcher either. (less timing so it works with Comp) Because, after all the threads out there on this subject, I have the impression that a CaTCHER's benefit is from both the maximum timing it gives and the fueling. With the Comp doing some of both the Catcher without timing has a lot of its potential already filled by that Comp. It does add more but not $500 more.
The Comp is also adjustable so that if you have massive injectors and low-boost smoke issues, you can put it sublevel-1 and defuel for take-offs.
Again, the catcher is the way I want to start my buildup. But for someone who already has a Comp, keep it unless you have the kind of money some do and can change $900 injectors every few months, then you can do what ever you want!