I'd go with the bivvy again (and some of my reasons are admittedly subjective/personal preference).

I like its softness and flexibility. My sense is that the Land/Shark is less flexible, if I'm correct in assuming it shares physical characteristics with Space All-Weather Blankets, a couple of which I have; and the Blizzard Bag strikes me as being a little less durable. Let me hasten to add, I couldn't find the Shark or the Blizzard at local retailers to inspect first hand. Since I could the bivvy, the benefit of hands-on inspection tilted the scales a tad.

Also, having spent an eternity wrapped in a single-ply space blanket w/sleeping bag one night years ago (the sleeping bag I brought was a miscalculation on my part), the ability to vent the bivvy was appealing.

And while it's somewhat more bulky as purchased (loosely rolled in the stuff sack) than the other two, the cylindrical shape packs nicely in my fannypack and daypack (doesn't hurt that it's featherlight too).

On that note, I should have mentioned that I re-rolled the bivvy so it's tighter, then secured with two ranger bands before putting back in stuff sack. Now, its volume is pretty comparable to the other two.

I liked the non-conductivity. Certain times of year, Arizona can get unpredicatable thunderstorms, and the lightning can be a sight to behold. If I can carry something that won't increase my odds of getting zapped, that's good.

In the end, it was, "Each of them requires some compromises; which are less important to me?"

So short answer, yep, I'd buy it again. In fact, I could buy two for the price of one of the others. <img src="/images/graemlins/smile.gif" alt="" />