John,
I will be interested to hear how you like (or dislike) the little 2.5 Leupold when you get it.
I've had one on my 400-350 NE double for about ten years or so. It works very well, and I find the reticle stands out pretty well in low light, even against a dark background as in a black boar pig or similar.
There are times when a variable would be better.
1-4 Leupold or 1.5-5 work pretty well on doubles in a variety of hunting situations IMO.
The 2.5 is lighter and smaller than those however, and maintains a better balance and feel I reckon.