Big +1 on Arc Alpinist by Nunatak, and ditto for service/advice by Nunatak.
The Arc Alpinist I bought 10 years (more?) ago is my favorite item, no doubt.
Assistance during ordering process was exceptional. Given cost of the quilt, really appreciated having all questions answered to be sure it was just right.
Ended up with sizing customized between "medium" and "large" (see sizing chart at link below) with differential cut, extra two ounces of down, and add'l half-inch baffle height (total 3") to allow for lofting of the extra down.
Finished weight after all mods was 24 oz; and that's for a quilt estimated for use down to 20 degrees -- before the extra 2 ounces of down that I had included.
Here's the link to the current Arc Alpinist chart:
Final note: When it appeared the quilt I ordered wouldn't be ready in time for a fall trip I'd planned to the Enchantments, Nunatak volunteered to send me a stock Arc Alpinist for that trip. The loaner quilt was great, but had Epic outer rather than quantum (as mine would have) so it was a few ounces heavier. But still, the loaner was an outstanding quilt, and it was provided "free" for that trip!