I've got a waxed cotton Barbour jacket and I can attest that it does work beautifully in serious rain. Mine was a hand-me-down, so maybe that makes it less pretentious?

In all seriousness, I'd be interested in a Bobbin cape if it was available in a more noticeable color than run-me-over-green. The cotton breathes well in Florida's insane humidity, and it's much quieter in the rain than synthetic fabrics.