Ryan is testing the Lightheart for BPL. He doesn't own it.
In any event, here are just a few quotes from Ryan himself regarding bivvies:
"However, consider the advantages of a bivy sack like the Unishelter: absolute simplicity in pitching and the emotive rewards of sleeping under the stars while remaining protected. My favorite feature about the Unishelter is the ability to remain warm and dry, securely cocooned inside the shelter, reading a good adventure story or writing in my journal, while a storm rages only inches from my head! It brings you in closer communion with nature's fury and makes you appreciate it in a more intimate way. The experience is capped by waking to clear skies, unzipping the door, sitting up, and brewing morning coffee while snapping photographs of the sunrise. "
"The eVENT floor of the Overbag/Bivy allowed me to flip the bivy over when using it as a standalone shelter in driving snow and rain. This allowed me keep the hood opening facing downward and protected from moisture entry. I was not able to do this with the Micro Bivy, because its coated floor would have resulted in prodigious accumulation of moisture in the bivy resulting from condensation."
"Below treeline, with the Micro Bivy, I simply moved my pitch so that the head end of my bivy was protected under the shelter of a tree or bush."
"For years, ultralight backpackers have scoffed at bivy sacks, claiming that outrageous psychological disorders will afflict the occupant. "Claustrophobia!" says one. "Modern day sweat lodge!" says another. Still others punch their calculators and thus deduce that bivy sacks offer space-to-weight ratios that, given the state of modern-day ultralight shelters, are as outdated as their HP-35's.
But what of it?
The bivy sack, in its purest form, provides a weatherproof shelter with a simplicity that has yet to be benchmarked by another design. Only in a bivy sack can you lie in the warmth of your sleeping bag and watch a meteor shower while being protected from wind and dew. Only in a bivy sack can you roll over in the morning, open one eye, and get a horizon-to-horizon overhead view of a magical sunrise. And only in a bivy sack can you arrive in camp, crawl in, and go to sleep: no stakes, no guylines, no poles, and no "good pitch" to survey."
"Now, I'm down to three shelters that I actually use on a regular basis:
A small bivy tent (my current favorite is the Nemo GoGo, at 1.9 lbs)."
Here is a picture and discussion around his ID Micro-Bivy:http://www.ryanjordan.com/weblog/2009/07/pine-tree-bivouac.html
Note that all of these comments are for waterproof bivvies without a tarp.