which ultralight zpacks cord:?

I use the z-line spectra cord and i really like it. I only use it for guylines for my tarp though and would not want to use it for bear bagging so if you are only set on one cord than go with the dyneema.

I've been playing around with the 1.5mm zline for my guylines and find that it holds adjustable grip hitches quite well. My only issue is that ti's really hard to cleanly melt the ends to prevent fraying. I've ended up tying double over-hand knots and trimming the cord about 1/8 or so past that, and just letting that much of it fray. For the most part, once I've tied the knots in my guyline, I don't really have much need to untie them anymore anyway. It's a bit stiff though when you first get it, like solid core copper wire, but it softens up with use.

I've also used the 1.25mm stuff with cordlocks for stuff sacks, and that works really well for that.

BM

I'd go with the slick dynema if your using it as guy lines and bear bag hanging. The slick surface of the dyneema really helps to minimize drag and vibration when your hanging a heavy bag of food. I'm sure it would work as guy lines as well but I haven't really tried it for that application, I have the two different types from zpacks.

I absolutely hated using the z-line slick cord for bear bagging…. I originally bought it for that purpose and tried it a few times and found that the line can just destroy your hands and dig into a tree branch pretty easily with minimal weight. I ended up using it for guylines (works great!) and purchasing the reflective glowire from mountainfitter for my bear-line:

http://lawsonequipment.com/All-Products/Reflective-Glowire-p881.html