If there was no psychic test involved I'd say the CWE version is far better but with a LD9 psyker having to test every turn you are going to be left out in the open with no cover and no veil at some point, at which stage you can kiss your incredibly expensive unit goodbye.
Mind you, with the amount of cover ignoring weapons out there these days, the DE version is not exactly brilliant either. Would anyone field these guys knowing that they are very likely to come up against the Tau at some point, who will just say "Thanks for the kill point" before wiping our little clowns off the face of..whatever planet they happen to be on!