Brian, the Hennessy's not the smallest, a common 15$ net from X-mart is about 1/5 the size, and about 1/4 the weight, but if you ever spend a night in a Hennessy, you won't settle for anything else. At about a foot long by about 5 or 6 inches around (in the stuff sack), and about a pound and a quarter, considering how valuable a good night's sleep is, I'd say it's one of, if not the most important piece of camping gear I've got, and that put's it pretty high up on the BOB list too.
Troy