I believe that Manny Bhuta, a regular on the old rec.photo.darkroom, used to own one. Try Googling him. My understanding is that they're a De Vere 504 with fancy electronics. If the electronics go, you're in trouble. They had a very high output head, which would only be a benefit for really big prints. Also, I believe the head was closed-loop, which would lead to very accurate dichroic settings. This would be most useful for color printing.
I've never used one, but I saw them often enough at trade shows and used to know the people involved. They're stunning (and yes, they are closed-loop), but they were blindingly expensive, and they've been out of production for maybe a decade. I'd be wary, though I suspect that if things do go wrong, you can repair the circuit boards: they wouldn't have used dedicated chips. Personally I'd go for a De Vere instead.
I own one of these pieces of crap.
as well as the earlier version the zbe b&W cold light piece of crap.
I spent very good money on these pieces of crap at a time when darkroom equipment was at full value.
I would not recommend zbe and its support service as it is crap.
Both units , though remarkable for their capabilities could not perform in a working darkroom. I have Omegas, Durst and Deveere as well as these two pieces of crap. I think I have no more than 30 hours on each unit.
Trying to get service on these crappy heads turned out to be impossible , and short of incredible zbe lack of concern with their users.
Owners of Chromiras should be warned of the potential crappy service afforded by the main company.
Did I say I thought they were crap??
Decent idea with crappy follow through on service .
I rate this company minus -6 out of a scale of 10.
Combined I spent 10k on these two heads in the mid 90's and they are in the parts shelf of my lab.