I have the big one, and it is a bit heavy - if I do a long clipping session, my arm will get tired since I cannot really let the clipper lay on some surface (plus I need to turn it to the side from time to time to get rid of the clippings). I'm still very happy with it though, it does a very good job. I didn't know they had a smaller (and hopefully lighter) version; the one I have cost me enough (with S&H to Europe costing roughly as much as the item) that I'm not ready to buy another just for the sake of comparison.
But then, the heavier tool discouraging long clipping sessions isn't necessarily a bad things; it's a boring task, so I'd rather not spend a whole afternoon at it. For most mortals (those who think a full ASL OB is a lot of counters, not just a small part of their collection) it should be acceptable.