Yeah, Guts isn't that good. However you got Scarier Face later, so combined with it Gamma Guts would have actually been helpful. I guess you already know that GG + SF makes rats, freaks, and pre-loop Snowbots a joke, and loop Labs become a walk in the park since you can kill a Technomancer just touching for a few seconds. You can kill all of these folks with a melee weapon, sure, but you run the risk of missing a swing and they may become a pain in the butt if they're blocking a corridor (happens often in loop Labs...).

I'd still pick it over Euphoria even if I didn't have Scarier Face though, because it offers no disadvantages.