I want to put one on my 92A1. I'm doing it for the greatest reason of all... because it looks cool and I can.

Just curious if anyone has one or used one, are they quality, do they screw with reliability?

Don't have a Jarvis but have had an Accu-Systems bushing compensator on my 1986 Taurus nickle PT99AF for decades. This is not a screw on but rather a clamp on affair. Beretta actually marketed their own version of this back in the day as well. It has a small angled wedge that forces the barrel nose to lock up in the exact same position improving accuracy. I was turned on to it by some Napa CA LEOs back in the '80s. And yes, it works very well.

If I may/sorry to throw another kink into your plans, I haven't used a Jarvis, but I had this 90-two with the "SGS-Style comp" sold by the guy named Ric over on Beretta Forum. It attaches via an included guide rod, and then centers itself on the frame. No customization of the barrel needed. It was heavier, looked dang cool, and made the gun the softest 9mm I've ever shot. but it was twice the price of your Jarvis one, IIRC.

Do the Compensators make the pistol front heavy?