[I posted this in boost.devel, but got no response. Presumably that was the wrong group. :)]
I'm going to respond, but I don't have much to say. I would think that with all the work you put into making this comparison that you could probably determine why smart_ptr is slower than yours. To me this comparison is interesting but not without comparing your code with smart_ptr. Given the lack of code, I have to assume you're waiting for someone to say something like, "WOW!!! I gotta get me some of that!"
No, I was seeking information, as I said. "There are environment settings for which boost::shared_ptr will perform much better. If that's so, can someone help me out with suggestions of what defines to make?" It turns out that there are. If I was wanting to make a splash, I'd got for a dip down at the beach. I merely didn't want to post a lot of proprietary code before understanding whether that was welcome. Thankfully, I've had encouraging responses on the developer group, and the code is now posted there. Cheers Matthew