I take Imperceptive Healer every run due to the challenge element, and because I like to believe that my character is free from blob infection until I start chugging mutagen. You play much more carefully when damage takes so long to heal, and first aid becomes a very strong skill to level. Especially early on, damage ends up being semi-permanent, taking several days to heal off of it’s severe.
Of course, my current run is a post-thresh medical mutant with Regeneration, and it mutated into Fast Healer anyway, so none of that applies anymore, but hey!