If you really want a waterproof shelled insulated jacket to use in the rain, it’s probably better to go for something with PrimaLoft or similar synthetic insulation, which will actually still work when it inevitably gets wet, which it will – jackets having neck holes and all. On top of that, most down jackets are too warm for conditions above zero when rain is actually going to happen – Rab’s shelled Microlight is a bit of an exception to that, but really I don’t see the logic in waterproof down jackets unless you’re climbing icefalls which are melting on you…
Rab quality? I’d say it was still generally good, they had some teething problems when they switched production to the far east and had to deal with a whole load of new factories, but I’d say it was on a par with everyone else’s. Their top-end down kit is still hand-filled in the UK, though the shells are made abroad btw.