I have a homemade chock that is a fairly decent copy of the wheeldock(it was in the trailer when I bought it). Problem is I need something versatile as I end up hauling all sorts of different bikes for my friends, and that design works great on some bikes but not so great on others. I'm not 100% trusting of the design, especially in a severe manuever like the trailer going off the road and through a ditch--bouncing the bike right out of the chock, so I'd still want to have a couple tiedowns for added security. (I've seen a few trailers wrecked horribly, yet have their properly tied down cargo survive without a scratch!)
I really like the biker bars too, but then again they wouldn't work well on motocross or sport bikes, although that is something I can add without interfering with my current chock.
I'm happy enough with the chock I have, just frustrated with the lack of points to hook a strap on the bike. Highway bars are sturdy, but over a period of time and repeated use, I'm afraid that tying onto the bars away from the mount point will cause flex and eventually cracks/failure.
The best solution for me would be a bracket for the side of the upper forks like MOCO sells for the batwings. Definitely a market potential for someone!