I already have a WM Versalite 10* bag that is great for a large amount of backpacking I do in my favorite places (alpine and generally above about 7000ft).
However some of the hiking I'm going to be doing here, and back in the UK when I move back, is going to be at lower elevation with warmer nights. I am a cold sleeper and don't know if it's worth going with a 30 or 40* quilt (what I prefer in warmer temps over a bag) in a synthetic bag (my preference for damper climates)
My thoughts are if the temperatures are going to be anywhere near freezing overnight I'd be taking my Versalite.
Also, other than EE who does synthetic top quilts as I know their temp ratings aren't great (personal experience) and Loco Libre Gear isn't currently listing them on their site