Thanks for the quick replies!
Elena Lee:
I'd looked at the MB Spiral Huggers a bit, but while they sounded quite comfy I'd heard it theorized that the stretch baffles can create some cold spots, not to mention that FF and WM tend to be a bit more consistent with their fill. None of this is first-hand experience, just what I've picked up from forum lurking. Then again, I've also heard them described as some of the most comfortable bags out there.
Not trying to be a snob-I'm still sure I'd love an MB SSDH! I'm just a student right now so I'm trying to slowly save up for the single best-fitting piece of gear I can in each category. Figuring it'll be cheaper in the long run than repeated upgrading :)
The Western Mountaineering bags are definitely something I'm considering as well.
Richard Lyon:
Really good point on the greater need (utility?) for water-proofing on the Wren than other bags, not something I had considered.
I actually hadn't looked at Nunatak before, and the quilt sounds intriguing. I know it's impossible to have an all-purpose bag without sacrificing a little in each area, but the BCB seems an excellent compromise for 3-season use.
As a quilt (and from the pictures on the link) am I correct in assuming there's no hood? It sounds like there's a drawstring to cinch up the ends, just wondering where my head goes!
Since I live in North Carolina, going to school in the cooler mountain climate but summering in the (very) warm Piedmont I'd actually been looking for bags warm enough for chilly fall nights with full length zippers to use as a quilt when it was too warm for a full bag. This looks like a lighter alternative since it's using Velcro closures instead.