Shovelglove is actually great for abs -- all the twisting. The original inspiration was the reportedly great abs of 19th century French coal miners. I haven't done a crunch or a situp in years and I have a discernible (if not exactly bulging) "six-pack."
As for legs, shovelglove focuses on the upper body because there isn't much useful work most of us can do with our upper bodies any more. So we have to pretend. But there is still useful work we can do with our lower bodies, and that's so much better than pretending: we can walk. Have you seen the urban ranger site and group yet?
http://urbanranger.com
If there's no way you're going to fit enough walking in, a bunch of people here have been doing squats as part of their shovelglove routines. There's no law that every move you do has to involve a sledgehammer. If there are other exercises, say leg specific ones, that you'd like to squeeze in, by all means do.
Hope this helps, keep us posted,
Reinhard