Is it really worth losing health or letting hem recover it though? Like I said, health>meter. Especially since meter builds really fast in this game.
It depends on the situation, if you're losing and you're just using clash like an MK style desperation breaker, then yeah, go all in, but there's other applications. It may seem at first that all in is the best mentality, but circumstances will definitely arise when its better to have an opponent with no meter and more life than the opposite. No meter means no push block, no ex, no bounce combos, no nothing.
Its really no different from the decisions marvel players make regarding xfactor, or SF4 players make about using half strength or full strength ultras.