I have a RayWay quilt (home made) with the Alpine upgrade and I've gone down to mid 20F's with it. It weighs 26oz with the stuff sack and is about the size of a volleyball. I typically use a hammock but have used everything on the ground also: 3/8 in. blue ccf pad, RayWay quilt, warm clothes AND an Exped7 down air mattress.
I picked it up on sale at MooseJaw. The Exped can inflate to about 1.5 inches. It weighs 34.15 oz. My ccf pad is cut down a little and weighs 9 oz. You could pair it with a fleece blanket to add some warmth and cut down on the potential for sweating due to the ccf pad. The two would probably add up to the same weight of the Exped.

When I hammock I just use the Exped and the quilt. If it is going to be below 20F, I have a hammock sock that slips over my whole rig and adds about 5-7F degrees. I do plan on making an underquilt this winter.

If you think you can, you can. If you think you can't, you can't. Either way, you're right.