I've several EE quilts and love them. Saving weight on the zipper and the worthless compressed insulation underneath you is what first attracted me, but I find a quilt much more comfortable (less restrictive) and that's my primary reason for preferring a quilt now.
My experience has been the same. I've used my 0 and 10 degree UGQ/EE quilts down to -25 comfortably many times. Unless I'm truck/horse/quad camping, I have no use for a bag anymore, regardless of the weather. I may change my mind in -30 and colder temperatures, but I doubt it.
