I'm surprised to see no mention of the Op/Tech Pro strap... it's really the competition for the Crumpler. In fact, a quick glance as
Amazon finds users seem to like the Op/Tech about the same, and it's half the price of the Crumpler. (The Crumpler may have an advantage in "breathing"... most people who didn't like the Op/Tech didn't like that it had quick-released, which is kind of why lots of other people - me included -
do like it. I keep a short set of quick-release connectors on my main DSLR even though I usually use the R-strap.)