Is there a reason not to use a thermal  scope as a stand alone monocular occasionally? I do some remote camping with my family and would like to be able to do a scan occasionally from our roof top tent (and not be sweeping a weapon). I'm not keen on buying a separate device to do that. Specifically I'm looking at an XP-50 or 38 scope when they hit the market but admittedly I'm new to the thermal game.

I could be wrong but is the Armasight Prometheus 42mm hand held mono and the Zeus 42mm scope the same size with the exception of the scope mount on the Zeus. I just bought the Zeus 75mm and bought the Zeus 42mm also I plan on using the 42mm as a mono when I use the rifle with the 75mm on it.  

Until the new pulsar monos and scopes come out.  I think the only issue you'd have is to verify your zero before hunting when you remount it on your rifle.

Zeus and prometheus are identical except the mount.

Good deal. Thanks for the feedback everyone.