I've had very good experiences with my Marmot Cloudbreak 30. It's synthetic and packs down to about 10" tall by 6" across with the help of the compression straps. However, I would not say that it's usable down to 30 degrees. Personally, I'm comfortable down to about 45, but I run pretty cold. Still, this is a great lightweight sleeping bag that is very appropriate for touring when nights don't fall below 40 degrees.

I'm in the market for a 0 or 10 degree bag for winter touring.