I think the Three Rivers racks are cool, and useful, but they are not as efficient as toaster-style racks, though I also agree with cburch's assessment of them. The rack in my office's loading dock is toaster style, but I can get my bike over the top bar, so I can lock the frame and the front wheel. This is, however, entirely due to the dimensions of my bike--I couldn't do this with my last ride, and just had to stuff the front wheel in there and lock that. Of course, the dock is closed 75% of the time, and the racks sits at the back of the dock, so I feel pretty secure there.
The overflow racks at REI in the South Side are okay, I think, as they allow you to easily lock the front wheel and frame.
All that said, it seems we want to have our cake and eat it, too--we want the convenience of quick release wheels, panniers, lights, etc, etc, but we also expect them to be safe. When I had to lock up on the street for a job, my bike had nutted axles, and I did chain the saddle to the frame, and I left NOTHING on the bike.