I haven't seen this discussed in much detail besides a couple random comments in other threads. I don't like to use trekking poles so ditching the tarp, guilines, poles, and stakes out for a heavier bivy would actually save me weight. Weight aside it seems like it might be a good idea if only to simplify my gear list.
Does anyone use a waterproof (goretex, event, etc..) bivy and go tarp free?
What are your experiences?