Looks like you've got a plan.
I'm attacking the shelter question on many gear fronts as well(tent, tarp tent, tent/bivy thing), only my equation involves winter camping as well as summer.
My goals were:
1)Cut my shelter weight at least in half.
2)Remain dry and keep critters out.
3)Minimize setup time and complexity as much as possible.
I looked at tarps, but I don't live in the desert, when it rains here we have mud and running water. I need a floor of some sort. The Bilgy tarp tent fit the weight and dryness mark for me, but it's still a tarp and requires staking out and a fair amount of room to do so. I need the sewing practice, and I think it'll make a nice way to go in the slower paced summer rides, so I ordered a kit to play with.
I looked at bivies, but they all suffer from condensation, and don't deal with precip all that well by themselves. You still need a tarp or something to keep dry in the light ones, and the ones that are considered weatherproof for winter weigh almost as much as a tent and still have poles and/or staking to deal with. Most of the bivies on the market seem to use so called waterproof/breathable fabrics to deal with condensation somewhat, but cost as much as a tent and still aren't rid of the condensation problem as the fabric still lies directly on your sleeping bag. From what I understand, part of what makes tents/tarps more livable is the airflow through, keeping moisture evaporating out most of the time. And then there's getting in and out of the thing. I just don't see myself struggling to wriggle into a bivy after being totally beat and freezing or getting caught in a middle of the night rainstorm as a good thing.
So I ended up settling on something somewhere between:
http://www.nemoequipment.com/nemo08-gogo-tent It's pretty small, it'll keep the water and critters out and my gear dry, can be set up from inside, no poles to deal with(till I pop one of the bladders on a cactus, but it can be converted), and it's less than half the weight of my tent(2lbs). I'd like to leave my bag inside and just roll the whole thing up and strap it to my bars for an instant shelter roll, but we'll see how much condensation ends up on the ceiling first. May not hold up to high winds either, but then it just becomes a big flat bivy. Either way, I'm gonna give it a shot.
For a ton of background reading on everything lightweight camping you should check out
www.backpackinglight.com. It's been a great learning resource for a lightweight camping gumby like me.
DG
