H2No is not a technology.
It's simply Patagonia's "standard" for "something" that is 100% waterproof, and breathable.
Within the H2No classification, Patagonia uses a variety of technologies, depending on whether the fabric is 2, 2.5, or 3 layer, and what the price point is (i.e., they *may* use different technologies within each layer class).
I have not been impressed by the breathability of their 2 layer technologies, but so what - they are mostly your run of the mill, fairly cheap, PU-coatings. No big deal.
I love my old Specter (2.5 layer), and found it to be *almost* (but perhaps, not quite) as breathable as Pac-Lite.
I also have their M10 jacket (2010), which is 3 layer, and is as breathable as any eVENT jacket I've used. Very impressive stuff.
Don't write it off. eVENT has competition.