I have had a Nomad JB3 since October or November of 2002. I have recorded about 350-400 field hours at shows in all kinds of conditions. I have pretty much never had any problems with it, except:
1) forgetting to clear the drive and having the recording of a show get cut short due to lack of HD space
2) breaking off the mini optical cable end that goes into the jb3 (I have always feed it a digital signal)
Problem (1) is obviously user error, no fault of the JB3. Problem (2) was a bit of an issue, as I went through half a dozen optical cable adapters. Since I've started using right angle adapter for the optical cable and taping it down to the JB3, I've had no problems. All in all, I think it is a very reliable unit.
BTW, I feed it an optical signal from an old Digicon DC2 scms stripper and format converter, which works great. Not of much help to anyone else though since you'll never be able to find one of these. Also, I still run a DAT backup, currently with an M1. The tapes keep piling up everywhere, more often than not I never even get around to labeling them. Still run the DAT though, don't ask me why.
-Todd