I have a Jacks R Better Sierra Sneiviler which can be worn.
I have to say that it is a bit bulky and dorky looking, but it works if you are standing around.
If you want to sit down to eat your dinner or just sit down period, the excess material can drag on the ground and get your quilt dirty.
It is not possible or practical to hike with it on....again, the bulk is the problem.
Could easily snag on brush or branch etc and damage it.
Wearing it and putting on a pack...don't think that would work either.
For me, I still carry an insulation layer because I can wear it while hiking, if I need to.
The benefit seems to be that while my insulation layer (Montbell Thermawrap Jacket) might be thin/light enough to hike in, it might be too cold when just standing around camp. Having the wearable quilt does a nice job in providing additional warmth.
Just prepared to look uber dorky.