UKH

looking for experiences and recommendations for a breathable bivy bag. Will be used for snowholes and bothy stays. Needs to be a decent size as I'm over six foot. Cheers. 

Army Issue gtx bivvy is generally pretty good, robust, breathable and long.
Ive tried more expensive lightweight ones and they never seem as breathable

Army issue is nice and robust, but it's a bit on the bulky and heavy side.

Another vote for army ones. I have a Dutch army one in supposed vapour permeable goretex, it is big, roomy and robust. Yes it weighs more than a lightweight alpkit or survival zone but that's still less than virtually any tent.

Thanks. Will have a look

If a bivi bag does its job and keeps you dry, any extra weight is soon compensated by not carrying wet sleeping bags.

In rain, the only times I have remained dry is when rigging up a small tarp, so as not to have to breathe into and through the bag.

I've got an Outdoor Research Helium. Almost no condensation in the mornings and it keeps out Scottish summer rain. I like how it's got a tent pole that keeps the ceiling off your face, and insect mesh. I'm 6'3" and I'd prefer it to be slightly longer, but it's not a huge issue. Expensive.