Hi Sandsnakes, I'm a big fan of hooped bivys but although I haven't used this particular one, from looking at the pictures it wouldn't be my first choice. The big advantage of a real lower hoop (such as in the TN Saturn) is insulation; having the bivy bag lifted off your feet keeps them much warmer (and personally my feet get cold first so that's important for a good nights sleep). No conduction from any snow / water on the surface of the bag, no compression of your sleeping bag insulation, and a nice big stationary air gap that's also good for insulation. It's the reason I much prefer the Saturn type to something like the Jupiter. I don't think the bottom lifters on that eBay bag would lift it enough to keep the material off your feet.
Regarding the whole bivy vs. bivy + tarp vs. bivi + poncho vs. tent vs. hammock etc I've discussed all that on here before. Everyone's different; if you're someone that treats camping as something to enjoy as and of itself a tent's probably the best option. The hex 3 (now Shangri la 3) is very good and roomy for one or two people, for solo camping a TN laser comp or Hilleberg Akto are both excellent. As someone who treats sleep more as something that you have to do at inconvenient times in the middle of something else (eg walking or climbing) I take a bit of a different view on the compromises involved so a hooped bivi is usually my first choice. I use it one or two nights a week almost every week of the year. On summits and rocky ground I can use it without any poles and grab some kip in short order. If it's snowing or windy or particularly nasty I usually use the poles and get a nice little warm and dry shelter far quicker than I could using a tent. It also has bug netting which I consider invaluable for some of the year. Yep, I can't sit up to change or read, instead I lie down to do both. Not a problem. I've played around a bit the last few years with tarps and bivis as well but they're too fiddly to erect well and too flimsy in poor weather IMO. I thought the extra space would be nice but in reality I'm more cosy in my hooped bivy. Much stronger too, even compared to almost all tents thanks to its low profile.
There is something to be said for tents, I'm going to be using an ID Mk1 Lite this winter season for trips of more than a few days; the ability to cook inside will make the weight worthwhile I think. Compromise should be worth it. All swings and roundabouts!
