I have a Leupold 1.5 X 5 IR. It is a VXIII, roughly 5 years old. It has the battery and switch on the ocular lens, the new models are located near the reticle adjustments. It does exactly as advertised, I find it most useful in deep woods. Over cut fields the scope alone will take me past legal shooting light.
This scope is built on a 30mm tube the non lighted is 1", I could not comment on the rest of the IR line especially the new VX3. The VX 3 is supposed to be a very nice optic, IMO better than the Monarch. It is also fairly expensive although price is all relative.
It is not afraid to use batteries, if you forget to turn it off don't expect it to be burning when you remember again. I don't know how long it will last but it sure ain't a week.
I would put the battery life at less than that of a Red Dot type optic, but the reticle is always available unlike the Red Dot.
I bought it for the AR but ended up putting it on my 1895 Marlin. I will say as the light fades you need to keep reducing the intensity as it will start to flare. If you do get that last minute shot, it would be a shame to be fumbling around I use it at roughly 2-3 out of the 11 steps and only turn it on about 15 minutes per day if at all.
