The only way I look at it is this way, an extra 120 hp is like an extra sin strike you can take from a rogue, or a melee crit from a warrior etc. Whereas the SP from the BOA trinket affects all of your heals, including the hot you're going to probably be having on yourself at all times, as well as the amount of damage your bubble can absorb. Not that it's such a substantial amount, but it is nice to have, not to mention the 2% mana gain you could potential get from tossing out SW
's on people attack your FC and getting the KB from a tick.