I've had a Rod Hutchy oval for about 3 years now.
It has stood up to some foul weather and never leaked.
I would recommend getting storm poles for it, just to add that extra stability in high winds.
There is room enough to fit a bedchair in lengthways but not much height due to the spokes of the brolly, especially if you lower the front extending legs to keep out the worst of the weather.
I have never bothered overnighting in so haven't tried to get an overwrap for it, I don't think Huthchy does one but other makes will probably fit, after all they are all pretty similar in shape.