Afaik hatteras didnt install AC pumps on any of the older and smaller boats, they used the galleymaid 32 v. Its a good pump, overbuilt like all galleymaid stuff but pretty much outdated. On the newer boats, i m oretty sure they do like all larger biat builder and use a mach 5 with DC back up
Benefit of AC pumo is thst they will last longer which is important for full time cruisers, live abiard and larger boats where the pump runs a lot. Most DC pumps used rubber diaphragms, impellers, etc. with limited service life. When i tried a shurflo variable speed years ago, it failed after a of years. I talked to one of their engineeers at the miami boat show who exokained that the diaphragm was designed to last a set number of hours. It may last 10 years for a light use week end boater but only a year or two in other use.
Pumps like th mach 5 or the shallow well pumps uses solid impellers that do not wear, although some cheaper shallow well use steel which rust and fail after 5 to 10 years.
It all depends on how you use the boat. If you soend a lot of time aboard with say 6 people or more, use a lot of water to rinse t the boat, etc... a DC pump wont keep up.
Even our older motoryachts were pretty much set up to run on generator. Newer boats even more so due to the lack of ventilation so having an Ac pump plus a DC back up is way to go