I just noticed, after selecting Vampire at the beginning of a new game, losing some HP then gaining in back through Vampire, that I now have 982.05/1000 HP. I suppose precision and not losing the tiniest portion of HP gained is important, but it kind of gives me the impression that I also lost 0.95 HP at some point, maybe. Perhaps rounding is more aesthetically pleasing and draws less attention to itself and is less distracting when I quickly check where I am at HP-wise in the middle of a game before I choose an upgrade or assess what I should focus on next.