In shopping for a replacement after I got home, I was divided over buying a new Dolica or upgrading to something a bit more professional, such as the Manfrotto line. Thinking I could save a few bucks, I looked around on eBay and found a nice looking Bogen Manfrotto 3221W. That particular model has been discontinued, but it had great reviews.
The "W" in the model number indicates that this a wilderness model intended for wildlife and nature shooting. Right up my alley.
The 3221W arrived at my home yesterday, and the first thing that struck me was the weight of the unit: ~six pounds! Fortunately, this came with a nice carrying strap, and the weight on my shoulder is not all that bad. I thought the "wilderness" designation emphasized its portability, but now I realize that it is really for its ruggedness. This thing is build like a Soviet tank!
Here's an ersatz Polaroid shot of the legs with the bottom part of the carrying strap in place. The release levers are solid. The whole thing is solid.
I'm also a little disappointed that this model doesn't have the low-angle adapter that is featured on the newer units. For macro work, I'll have to either mount the camera upside-down on the center column or really splay the legs out. Still, I can't wait to give this a try. The real test will be in how I can transport this thing when I go biking.