My battery powered Dunlop Fuzz Face exhibits about the same hiss as my AC run, metal-gain set up. That's not too bad really but there's always a "Hum Head" in every band or session. It's usually the keyboard player or the sound guy and can be a serious point of contention. Be the buzz boss!!!
I have 3 Sunfaces and they are all pretty quite, the high gain NKT has a tad more hiss but I expected that.
I have 2 JMI boxes, a MK II and a Supa...they are both quite as a mouse from off to half way up on the attack...past half the Supa stays quite to full but the MK II gets a LOT of hiss in it.
My Fulltone Ultimate Octave is dead quite unless the octave up side is on and even then it's not too bad.
I guess at the end of the day it's just a roll of the dice!
Yes and no, as most of the answers indicate. Party it depends on the gain structure of your setup. Give us the components of your set up and it may be easier to diagnose. How much signal is going into the Fuzz and what kind of amplification follows. I would suggest that the more prized low gain germanium such as the OC and NKT were a transitional product before more common silicon and were subject to all kinds of production and use problems. Heat/noise, failure etc. From a good sized pile you can find some that meet the requirements of use but it is a mixed bag. I would plug a TGP member but it’s probably inappropriate. I suspect he is the only one with a large enough pile and the correct test equipment to determine good from bad. If I had one of his in question I would send him an email