BOB Coz Trailer
 

I found a good deal on a slightly used BOB trailer, one of the older COZ models with the hardshell cargo container. Has anyone here used one? I am a bit concerned about the one-wheel design, and how stable it may be when loading and unloading. Any thoughts would be appreciated.

The main advantage of the BOB is for off-road touring, because there is only one wheel and it tracks in the same line as the bike. But groceries are heavier than a touring load, so they may make your bike + trailer assembly wiggle a lot.
As for actual observations, I would suggest you read Alex Wetmore pages:
- this one for the Bob Coz;
- this one for the Burley Nomad.

I haven't driven one, but I have seen 2 BOB trailers at the market and quite frankly, I found it so small that I easily pack more stuff in 2 panniers, let alone 4! If you are looking for something cheap and mostly for errands and other short distances, look around for a used child trailer. I have one that I used for about 3 years for its intended purpose, and that I now use exclusively for cargo. Except for the wind drag, a child trailer works as well for cargo as a genuine cargo trailer, so while I would not recommend one for touring, it is perfect for shopping and other duties.

Thanks for the feedback, I was concerned about just that. While its a great deal in terms of $$, I think I would not be happy with it in the long term.