Saying "temperature rating" and "clo" in the same sentence as quilt sort of makes me laugh.
We do it at BPL, too, so don't think I'm not picking on anyone else, and am happy to point fingers back at myself.
But there are serious limits to attaching a temperature rating to a quilt because one's warmth while using a quilt has a lot more to do with their understanding of what makes quilts fail.
Of course, if you haven't read this yet, and then tested the theories and observations that are outlined in that article at least in your backyard, then don't go any farther, or you'll never be able to make sense out of any of this. Ideally, spend 7 straight nights in temperatures at 40F or lower. Come back to the forums every day and share your experiences and ask for advice, and by the end of the seventh night, you'll have figured it out.
There are meaningful differences in insulation quantity between MLD and BPL quilts. BPL quilts are heavier and thicker and offer more insulating insurance for less experienced folks at cooler temperatures, or ULers that want to push quilt limits to winter temperatures. MLD quilts are lighter and should be considered for more experienced users, or less experienced users in warmer temperatures.
As far as insulation "types" go, the industry now borders on stupidity trying to differentiate any of this with dry clo values. BPL's insulation was developed specifically to minimize loss of air void volume in response to the accumulation of moisture. To this end, there are big differences in insulations out there. However, if you keep it dry, it's really only about thickness - the differences between all of the major brands of dry insulation is minimal and reported clo values are best used by marketing departments, not users. There are differences in clo/weight ratios, but even then, they're pretty small considering the amounts of insulation that we are using in our quilts.
I have hundreds of nights in a quilt. I use the BPL UL 240, with the Cocoon Hoody and Pants, year round. Summer night temps for me in the northern Rockies are usually 25F to 40F, and I take this system down to the single digits pretty easily without too much effort or thinking, but prefer to use a cozy down mummy bag below about 15F.