Appreciate the feed back thus far.
I've got a page full of different bag's comparative dimensions written down. I agree that a 62" girth seems to be somewhat of an industry standard. So far I've found that the Mountain Hardware bags are listed as more generously cut than most of the others, so they are on my short list.
41magfan, you mentioned the Wiggy's bags. They are another brand that have also piqued my interest. Do you have any firsthand experience with them? I've tried to find info on them, but so many of the reviews seem to be an either/or, love 'em or hate 'em type thing.
Most of my use for the bag will be backpacking and canoeing so weight and space are important to me, too.
Again, thanks for the thoughts, guys. Any others?
What little I know about Wiggy's:
First off, Wiggy has used Climashield insulation since the get-go, which has been a looooong time. He laminates the stuff to the shell fabric with a method of his own design and calls in Lamilite.
All "continuous filament" synthetic (there aren't many in existence) insulations are bulky and heavy relative to other synthetic insulations, but they work like no other synthetic insulation, as well.
If you compare apples to apples, Wiggy bags aren't heavy or bulky - which is an often heard complaint. If another synthetic bag is smaller and lighter, it isn't the same insulation, the same fill weight, the same size, the same shell material or the same zipper. - simple as that.
Now if another synthetic bag with a smaller zipper, a lighter shell material, and less and/or different insulation works for you, I'm perfectly OK with that but it isn't a relative comparison.
Along those lines, I routinely witness people trashing Wiggy bags then brag about another product made with the same Climashield insulation as being the greatest thing since sliced bread. Ignorance seems to know no boundaries.
Mr. Wiggy (Jerry Wigutow) can be rough as a cob! A LOT of folks take issue with his products because they take issue with the man's temperament. I'm perfectly OK with that to be honest, but have the balls to call it for what it is instead of making silly comments about an insulation product with a well established track record.
I'll be honest, if weight and compression size are absolutely critical factors to your endeavors, I just don't see a synthetic bag - of any manufacturer - being the best choice if the temperatures encountered are below freezing.
My outdoor activities are totally benign - I backpack in the Fall/Winter on established trails. Weight and pack volume is critical, so I don't use my Wiggy bag for those pursuits. However, if I knew my life was going to depend on my sleeping gear, It's the only one I'd likely consider.
Incidentally, I've made the switch to quilts and my newest addition is a 20 degree Climashield product that weighs just 34 oz and stuffs in a sack that's about 8 x 12 inches.
Sorry for the protracted post ..... I generally refrain from using two words when one will do and contrary to what this post may lead you to believe, I ain't a Wiggy fanboy - I just lack the tolerance for BS. I've only owned three of his products, but they work as advertised and they're very reasonably priced.
Lastly, Wiggy offers a guarantee that his bags will not lose loft or fall apart with normal use and he encourages you to wash his stuff as often as you like. NOBODY else in the industry offers that warranty because their stuff won't stand up to those claims.