I have been using a Bell 995 and a Vedetta now for a while. They play very well together indeed. Their range is almost identical but the vedetta doesn't have exact freq display which is nice and the bell fills in this void.
Observations The vedetta will sometimes show a ka band when confronted by multiple k band store openers The Bell sorts them out a lot better.
The vedetta will distinguish instant on a lot better then the Bell
The bell shows multiple short shots as C/O as the signal alarm lingers a lot longer
I have noticed this about Cobra - detectors. They will pick up a policeman doing multiple shots far better then Bell units that will show them as a constant source quite often
I don't know about the newer bell units in the 300/500 series but I suspect they may do this also.