In reply to twm.bwen:
I'd say the key question is whether the hood fits over a helmet and still works - if not, forget it, that is an absolute requirement. Fabric weight/robustness is very secondary.
The other important factor is what else you'll be wearing. I went on one of Mr. Kimber's courses last winter and used a TNF Paclite jacket for rainy walk-ins in preference to my big full-spec mountain waterproof. There was some initial scepticism but the hood did fit over my climbing helmet and I was using it in conjunction with a RAB technical smock (thick pile-Pertex with a big wires hood) so everything was fine. If I'd been using it on its own over a fleece I don't think it would have been enough.
BTW, I've never had any RAB gear fall apart and would look at their Latok, Latok Alpine and Super Dru or perhaps the Crux flak jacket if I was starting from scratch.