I have had a powermaster one wire on my 57 for about 7 years and no problems. The following year I put one on my 34 and within a year the internal regulator went berserk, over charged and blew up the battery, and scorched a lot of wires. Lucky no fire. Oh, and when it happened I was out in the eastern Kentucky, 125 miles from normal civilization.

When I got the regulator and wiring fixed, I had it converted to a 3 wire. that was 6 years ago and no problems since.

Therefore I offer no opinions as to your choices, only my little tale of two alternators.