In my opinion, constantly worrying about using only the best RAW converter is a notion of a nature similar to constantly worrying about having the best lens or the best body or the best camera bag, ad nauseam. It does more to get in the way of doing photography than it helps. No camera is perfect. No lens is perfect. No software is perfect. Nothing is perfect.
Couldn't agree more . . . . erm, except that lenses really do matter, and I guess that the Leica 50mm f1.4 'lux and the 75 'cron are as close to perfect as one is likely to get. I fixed on Aperture a couple of years ago as my software of choice, and imperfect though it may be I've seen nothing to make me change my mind.
But if you're spending weeks testing RAW conversion software, and, as you say, they're almost identical, it sounds like you aren't taking your own advice - sounds like ad nauseam