Dewalt vs. Festool for cordless Ipe countersinking

I have been running the Dewalt DCF850 impact driver for years on Ipe installs, but the inconsistency in depth control when countersinking for plugs is starting to cost me too much time on finish work. I am doing a 600sqft job in a high-UV climate next month and cannot afford blown-out holes or scorched edges. I am leaning toward picking up the Festool C 18 with the CENTROTEC depth stop, but that is a $600 investment just for the pilot work. Has anyone actually seen a significant reduction in bit breakage and ruined board faces switching from a standard impact to the Festool system on 5/4 Ipe? I am tired of buying cobalt bits by the dozen and chasing depth on every board. Is it worth the switch for the precision, or am I just buying into the brand tax?