They do have a lot more cranking power which is a good upside, also having plenty of voltage is a plus
Dowsides, more $ up front for battery and chrager, will need charged every round, when a 16v goes low it takes a lot longer to charge.
IMO a good Napa Orbital or 2 if you have room, and a charge every round will be fine.
I had to move my vac pump so the alt would fit.