I have a whole set of these wrenches. I decided to get these due to the overall length, the look, the price, and almost every gearwrench tool I've bought I have liked.
So the length is perfect. They are a couple inches longer than your average "cheap wrench" giving you that extra bit of leverage that you need. The size of the open and box ends...rather the thickness is less than that of a cheap wrench. Meaning you can get these things into spots that you couldn't get a Harbor Freight wrench in to. I use a lot of Snap On tools and I really like their wrenches, but they are TOO EXPENSIVE for something that gets used so little. I use this 21mm on one or 2 cars a week. That's not often enough to pay more than this, for me anyway.
One last cool thing is that the open end does have grooves inside (Similar to Snapon) to help better grip the faster and prevent bolt rounding. It is pretty effective but still not quite as good as SnapOn.
All in all I would buy this wrench again, assuming I lose it, or it explodes, or some other castaprohe.