Heal over time makes sense if it's substantially more eco than direct heal. We already have resto (L/UL) for this.
I'd prefer direct heal, but to make sense (i.e. attractive vs other FAPs on the market), either it has to have
1) low/medium heal but high eco (>20 hp/pec),
or
2) average eco but high direct heal AND/OR high heal/sec.
I'd say that a Refurbished VII (upgrade from the VI we have so far) should be on pair with adj hedoc-50 at the very least. It will be most useful for low/medium level players. For high level players we have Neff's stim pack.
umm i want to remind u something here:
A big heal is always overhealing in a direct heal process, i use a direct heal and i pay for it, so unless is an eco similar to imp/mod fap, is always a loss each time u overheal yourself doesnt matter how less u pay compared to best tools, and i dont believe MA will alow a mod fap here on Cyrene, like ever.
A big heal means always more than your HP can handle, everything extra costs money, that is why when u do pvp this detail is not important.
for the options u mentioned, i dont see a much difference from what already exist in game, tho i would chose another option that is not yet in game
small heal and high reload, to reduce the cool down buff, and yet allowing u to not overheal u much cause the heal/use is based on that eco u said about. A high heal/ second is giving u this high price/ use, when a small heal/use has a diminished price , both in the same range of eco/heal.
i.e.
30-60 uses/min - 3-55 heal - 4-30 hp/pec
rank1 - 30/min, max heal 3, 4hp/pec
rank2 - 35, 4, 5
rank3 - 40, 5, 6
rank4 - 42, 6, 7
rank5 - 44, 8, 10
rank6 - 46, 10, 18
rank7 - 48, 15, 21
rank8 - 50, 25, 24
rank9 - 55, 40, 27 = 37 heal/sec ( mod 2350 = 41 heal/sec )
rank10 - 60, 55, 30 = 55 heal/sec ( mod 2600 = 48 heal/sec )
ranks can go on ..
just sayin'