two person ultralight quilts

EE accomplice….I could recommend it all day, every day.

http://www.enlightenedequipment.com/accomplice/

I have the Nemo tango duo. Bought it with a 20% off at REI last year. It's pretty good, except I wish it was a little wider. However, it does button to the Nemo slipcover for the two pads, which is very nice. Thinking about returning it and getting the EE accomplice just because everyone seems to rave on EE.

ZPacks™ 900 Fill Power Down Twin Size Quilts

Jacks R Better Mt Rogers and Katahdin-

+1 for zpacks!!!

But really you can't lose between them or Tim

I have a 20 degree ZPacks quilt. Like it for the most part. Great in weather 30 to 50. After that I want my own bag.

Synthetic quilts are really easy to make, and the materials are inexpensive and easy to find (e.g. owfinc.com). They make a great first-time project.

A couple of companies sell kits, I got one from RayWay Products and the instructions were excellent.

We've been very pleased with our zpacks twin. Apparently hammock gear will make a custom twin as well, it's not listed so I dunno the specs, but its referenced in their faq. I do prefer the feel or their argon to zpack's pertex.
To add to that, the 20 degree rating wasn't quite accurate for us. The lady had to wear all her layers to get warm in the lower twenties. I was ok in base layers, but was glad we got longer than we needed so we could pull it over our heads.

The only setups I've found satisfactory are a Western Mountaineering Aspen with Summer Coupler, good in summer and shoulder seasons, and a double Nunatak Back Country Blanket (BCB) arrangement, good in winter also. I describe the latter in my addendum to my BCB review on BackpackGearTest.org – http://tinyurl.com/7slg7h

Quilts do help in couples bags by allowing each sleeper to adjust ventilation. They don't help much in blanket wars, as described in my review.