In reply to abgeneigt:
Theta AR has been a benchmark waterproof/breatable-jacket for a couple of years now. And yes Arc'Teryx does new stuff, but usually doesn't change a working formula (Theta AR, Beta AR, Alpha etc.).
So if you get Theta at a good price just buy it.
Just a thought though, do you really need a w/b-jacket and would a softshell do.