400,
If you can hold the 10X still enough to use, I would get them. I have been using Nikon 7-15X35, which weigh about 31 ounces, in a bino-budy. It is very nice to be able to turn up the magnification. From my experience I had to lean against a tree or something in order to use the extra magnification.
In spite of the negitive folks here, I have found I can see the same detail with my Nikon on 15X as I can when I use the Minox 15X58 in itss tri-pod. You should get them if you like them. If they don't work out, sell them next season since you're not into them for very much.