I tried one the Black Diamond Lightsabre bivies and I didn't care for it. (see http://www.trailspace.com/gear/black-diamond/lightsabre-bivy/).
What I found out about bivvies:
*Bivies were originally made for someone hanging off the side of a cliff, where the options are a bit limited.
*Bivvies aren't very light.
*Bivies can be expensive for the features delivered.
*They are difficult to get in and out of. Not a deal breaker, but it is annoying and a real pain if it is raining.
*You can't do anything if is raining or the bugs are thick. Some like to use a small tarp or poncho in conjunction with a bivy to avoid this issue, adding to the weight and complexity. A simpler, lighter and less expensive "sleeping bag cover" is another option to use with small tarps-- just something to cut the wind and rain that gets by the tarp.
*You have nowhere to stash your gear-- your boots, pack and the rest are out there with the weather and critters.
*Bivvies are a single-wall shelter and suffer from condensation.
With all the nice UL tents in production, I don't think bivvies add up at all. I do recommend more flexibility as to poles and such, as it will open all kinds of options for you. Many designs use just one pole, so it's not a lot to deal with. If you are below treeline, a stick is all you need.
My SMD Gatewood Cape uses one pole, 6 stakes, one guy line weights 11 ounces and doubles as rain gear. There are shelter-only versions too. All are a thousand times more comfortable than a bivy, cost lest and weight less too.
I appreciate what you are after. I went with a GoLite Utopia 1 in an effort to have a simple freestanding shelter after dealing with a "freestanding" double wall tent that needed TWELVE stakes for a stable pitch-- which is ridiculous. I drool over Henry Shires designs too.