Well I dont have a jarbidge yet but I just ordered the regular one for my girlfriend. I have a DIY Climashield Apex underquilt that is just slightly shorter than the Jarbidge. I have to say Apex is great stuff but at just one step down I believe Paul uses the regular Climashield for the base Jarbidge so its great stuff too.(someone correct me if I'm wrong) Difference is warmth per weight of the fabric. where as 6oz sq/yd Climashield is usually rated around 30* most people will rate 5oz sq/yd Apex around 25*.
So to sum it up you get a little more warmth with a little less weight using APEX. Its up to you to decide if that is worth the $50 to you. For my GF it wasn't worth it because she isn't willing to be out in those colder temps anyways and her pack is so light already because I carry most of the food and ect items.
Down vs. synthetic is a whole nother comparison. I'll give you a couple quick points though:
Down looses all warmth when wet, Synthetic does not.
Down will pack down smaller.
Down will weigh less for colder temp ratings. some say past 40* or 30* ratings down wins out in weight.
Last edited by barbermike; 11-01-2012 at 07:35..