Originally Posted by Drip

You could divide them between some girls. For example, a girl with Counter Attack or a passive defense buff would probably benefit more from a DEF ampy than any other girl, while girls with an ATK+ passive will get more milage from ATK ampies.
Another thing to consider is, that ampies do give some experience. At higher levels, it doesn't add much, but below lvl 40 the increments are still fairly noticable.
Not sure where to feed the Health ampies, there aren't any passives doing anything percentile based with health, so I'd feed those to the waifu.

Yeah, they work like Level 5 manyus (720 exp).

ATK ampies are also beneficial in powering the ATK of lifeleechers (e.g. Alpinia, Kerria, Bride Camellia, Gerbera, Night Phlox, Oncidium). On skill trigger, that translates into more HP absorption from higher damage.

The same units can make great use of HP ampies as well, so as to optimize that absorbed HP by minimizing turnover due to a low health pool.

Originally Posted by JDSan

This is the first time I'm hearing of this bloomed form, is that the evolved form that maxes at level 70? or is there some additional thing eventually coming?

Level cap is 80 for "bloomed" units.