Best I recall torpex was 1.5 times the power of equivalent weight of TNT, AMATOL was 1.1, PBX was something like 1.6. Assuming my recollector is recollecting recorrectly at my age.
We had Mark 46 (obviously, an SH3D could carry up to four of those but the 46 weighed about 500 pounds versus the 48 3500 pounds, unsuitable for a helicopter) which was about the same size as a cutie, and the warhead was pretty close, something like 96 pounds. Main difference was speed and range, 12000 yards at 40 knots since a cutie stood no chance of chasing down a modern nuke sub at 12 knots with less than half the range.
Comparison is kind of idiotic to me, hit a sub with either one (except those titanium double hulled bastards the soviets were building which required the low yield nuke) and it's a kill, but a surface ship? 96 pound warhead versus 650 pound warhead? Mark 48 would kill a destroyer with one (or at most two) hits, but four Mark 46 hits would just piss it off. Same with the cutie versus a real torpedo.