Thanks to all.
Owen, John, and others--thanks for confirming Katabatic's reputation for quality. I'm not opposed to spending over $400 on a bag, but if I do, I'd like it to be one of the last bags I buy (well, at least for another twenty years).
I hadn't considered overfilling a Chisos--it's an interesting idea and I recall the Nisely research Eric and Delmar mentioned about down density increasing warm for a given loft height. However, since I'm right at the edge of Katabatic's size range for small (I'm 5'6") I wonder if overfill won't shorten the length of the quilt enough to cause problems. If I jump up to the next size, and then overfill that, the (slight) weight and cost advantage of overfilling a Chisos vs. buying a small Palisade disappears.
I considered having the Vireo overfilled as well, so the top half would be a few degrees warmer, but realized that would prob. make it harder to use in the 40s, since there's no zipper or other way of opening it for ventilation. The Vireo is still a very intriguing bag--I'd prob. have to get a warmer puffy than my MB Down Inner to use into shoulder seasons.
Rick (NYC): I understood you to mean 'fabric magic' as a complement. The Enigma's still high on my list--plus, I remember when Tim Marshall was just a guy posting quilts he'd made on the MYOG forum, so it's great to see him turn it into a successful company. With regard to your larger point, I'd like to see manufacturers specify baffle height rather than loft. That combined with fill weight (and fill power, to some extent) would make it pretty easy to compare, AND get some sense of how overfilled the stock bag is.
Eric, as far as I know, EN ratings don't apply to quilt-style bags. Don't know if they apply to hoodless bags or not. And even if they did, the expense may put EN rating out of reach for cottage makers. I don't see how assuming more or less the same temp rating for two bags with the same fill weights, baffle heights and fabric types is problematic. Nor do I see how a non-EN rating company could maintain its stellar reputation for decades, resist the pressure to move production overseas, continue to command premium prices, AND get away with exaggerated temp rating vs. EN rated bags. But I realize this is an old debate.
Rick M. and Ian: I was a little worried about some of these choices being too narrow--then I measured my Golite: 49" at best. And it works for me. So I think any of these choices will be okay, if not roomy. Most of the hooded bags (including the Montbell) are there for comparison, rather than something that's really on my short list--I don't like hoods enough to take the weight penalty.
Ken Larson: Thanks for the updates to the spreadsheet. A couple things: the length of the Vireo I'm looking at *is* actually 62" (5'2") rather than 6'2". And I'm (perhaps naively) considering any fill from 800 on up to be more or less the same under field conditions. I appreciate companies (like EE) that offer treated down as an option, but don't see myself as an early adopter. In the case of Katabatic, this means going for a nominally higher FP. In the case of EE, going for nominally lower.
Again, thanks to everyone for commenting.