RE: GorTex or eVent ?
Is the answer perhaps that life is too short to worry.
There is some benefit in breathable "waterproof", but its not perfect.
If you've got more money than sense, by all means buy Archteryx
If you're strapped for cash Regatta Sympatex will do a job for you.
In both, despite claims about waterproofing and breathability, if you work hard you'll get wet from sweat, if it rains really hard you'll get wet from rain.
The only ones who'll gain from people sitting round, believing that one fabric has a magical superiority over another are the manufacturers of overpriced gear.
I once went for an interview with a drinks company. They'd just bought a factory which bottled water for supermarkets. They stopped supplying supermarkets and brought out their own brand water. Exactly the same stuff, but retailed for about 5 times the price as when it had been supermarket branded. THAT is the kind of thing which "premium" branding does, and THAT is why marketing is a fancy name for conning people and exploiting them.