My name is Joshua and I myself will be thru-hiking the PCT in 2011. I have been looking alot at bivy/tarp as a primary shelter; MLD superlight being the primary bivy and not sure on the tarp yet. I was curious from your experience would you recommend the full net hood for the Bivy or the half moon window? Also any other recommendations about what gear you recommend would be so much helpful. Thank you so much
Congrats on undertaking the PCT! I suppose you've come across my PCT prep blog at http://budgetpct.blogspot.com/
Being an UL advocate and the owner of a Russian-language UL online community, I have a lot of thoughts and opinions on gear!:) Let me share a few, and if you have more questions I'll be happy to give input.
Bivy + tarp works well. Most of the time you won't want to pitch the tarp at all, and just having the bivy will save you time and effort over all the people with tarptents.
I would definitely take the full net hood, but I have never tried any other kind of bivy. What I found on the PCT is that heat is more of an issue than cold. Chances are you'll have a warm bag/quilt for Sierra temps (in 2009, it was 26 to 34 degrees at night for the first 20 days of June) that will feel like overkill for much of the rest of the summer. Having the netting will allow for more airflow.
I found myself at times thinking that perhaps a bug bivy would be more useful than a bivy much of the time. It would have been nice to have a bit more bug-free space, particularly around the head. For instance, I never tried eating more than small snacks inside the bivy. With the full screen, you'll also be able to talk to other thru-hikers more easily while in camp.
If I did it again I would probably take the MLD silnylon poncho-tarp and figure out a better solution for the problem of attaching tie-outs and avoiding tangling (I think I have a good one, but it needs testing). I have since sold my cuben poncho tarp and bought the more functional silnylon one, despite the additional weight.
An even lighter option is the Zpacks Hexamid plus some kind of rainwear such as a 200 gram poncho. You'd have more space to relax in buggy areas but would have to set it up almost every night, meaning less flexibility. I personally am nearly torn between these two options, but the Hexamid + poncho or light rain jacket combo is lighter even than the poncho tarp + bivy combo.
As I think I mentioned in my blog, the Golite Chrome Dome allows you to wear shorts and short sleeves in SoCal, avoiding much discomfort and grimeyness. I don't think I used sunscreen the entire time. A lot of PCT'ers agreed that it was a good idea, but didn't like the idea of choosing between poles and umbrella. But when I asked, most weren't 100% sure they actually needed the poles. For many poles seemed to be something they thought they had to have as backpackers. I, too, started with poles and used them plenty in the Sierras when crossing innumerable streams, but sent them home from Truckee and almost never regretted it.