Making horsepower has a cost. If that means you have to replace a $700 cat every couple of years to make 750whp then that's just part of the budget in my opinion.Seems fine to me as well. I do have to ask though because I really don't know. Do the other mods burn out the cat faster? If yes then it's more than a 9rwhp difference to make it all work. On the other side, a little R&D and of course a lot of cash and you could probably have more power while being cleaner.
I've been down the car delete everything side and the smell alone was super annoying.