Thanks for all the nice comments. I doubt it's really any more expensive that getting a window awning package. Plus with the window awnings, you have to drill a bunch of screw holes.
On the Oliver, the brackets to mount the awning are molded into the fiberglass hull. So it's about as sturdy a mount as you could get.
Oliver is the only ones I've seen offer this, but I suppose others could retro fit one. The story goes that the owner of Oliver didn't like to hang out with the wife and all her chatty friends, so he wanted a full size awning on the other side to get away from that. Who knows if that is true, but it makes a funny story.
I can see this being really useful if you sell at flea markets of festivals. Even tailgaiting football games. In the RV parks, as was stated above, you only really have room to extend it enough to use as a window shade.