Outside of looks, is there a good reason [to] purchase a titanium exhaust? I cant imagine they flow better than a mandrel bent system and when it comes down to it, isn't better flow what we're after?
Regardless of dyno used, HP increased by 22% (using your approximation of 81hp gain from stock). This is the only "number" you could use for comparison from dyno to dyno and it looks to be inline with what others are getting with catted downpipes.
I didn't have many issues with the Mustang but only had 36k miles on it too. Ironically, the left headlight went out after a couple months (2500 miles if I remember right), we had a cracked fitting on the oil cooler that required replacement around 10k, and the a/c went out around 25k (cant...
C8 and GT350 have been on my radar but with the HP bump for the 2021 and the impressive skid pad performance the 2020 already has (which should get even better), I just dont think there is much better bang for the buck. If the tune and downpipe deliver similar increases to what the 2020 is...
I think it's only 150lbs but yes, should perform a wee bit better.
Edit: I hope it's as responsive to a tune/downpipe; could take it to about 540hp on pump gas if so.