Cheers again for the responses...
If togging locally or getting the bus, I do prefer to walk as much as possible and I have been known to walk as far as 6 miles (on footpaths) with the Kata on my back...
I figure that a) I can literally keep all togging equipment at a central point, with bird and wildlife guides stored in the utility compartment b) It's very waterproof c) has rubber wheels, so I can go to local sites early in the morning without waking neighbours up and d) It'll save my back.
Erm...good point re carrying the case with weight being on one side. I find that this kind of thing doesn't affect the back, just feels like my hand is being pulled away from the wrist..I tend to experience sever discomfort when bending over then trying to straighten my back again, no so much sideways stress...
As for the size of the wheels, I can imagine the limitations. I think the wheels are a little larger on the im2720, but still not large enough to mean wheeling the case everywhere. My only remaining dilemma is whether to get the case in olive green or the more common black, bearing in mind I'm very much into wildlife togging..Mmmm..I can get the black delivered immediately or will have to wait 2 weeks for olive green...
Cheers again. Really appreciate your opinions

PS. I've managed to locate a retailer and negotiated a substantial discount, compared to other Storm dealers..
www.galeforcecases.co.uk