Had one for years, kept the rain off (light/medium showers- not been caught in anything too heavy) but noticed the bottom of my sleeping bag (MOD 58 pattern) got a bit damp with condensation on warmer nights. Nothing serious, but I noted it. I like that it has a wire reinforced fly screen so you can be totally enclosed, keeping the critters out as you lay beneath the stars.
Got mine for £50 years ago. It's been fine but other then the ability to be completely enclosed, I don't know if I'd pay the same now that there are cheaper(?) alternatives such as the Alpkit Hunka etc.
Ps, I'm 5'10 and leg room is tolerable but a bit frugal with my big puffy 58 bag + full length thermarest clone in it.
Still, slept in it maybe a dozen times over the years and always had a good nights sleep and woke up dry.
Pps, it folds up neatly into a small pouch in the foot plate (bit like a kag in a bag-and about the same size) which is handy but it's like doing a chinese puzzle to get it to fit