In a hypothetical situation where there are 2 cops, one shooting contant on, the other instant on further down the road, then I'd say that the V1 is the only detector that would give you a quick read on the situation.
As I'm coming up the road, the rx65 would alert full strength to the contant on source and ignore the instant on source,
the x50 would show me the constant on on the threat display, and then if I happen to be staring at the screen at the exact millisecond the instant on is shot I might just happen to see the tiny blip of the second source.
On the V1, I would be warned by a bogey lock tone and the bogey number going to two. So there is no chance I'd miss noticing the second cop and his instant on.
Being the only detector with the bogey lock tone to warn you of additional signals, the V1 is the only detector on the market that can really reliably warn you of multiple instant on threats.