In my opinion, the best thing about a membership to the America West Club are the reciprocal privileges that it has with CO President's Clubs. Actually, with the membership comes access to the TWA Ambassador's Club in CMH as well.
The clubs in PHX are nice enough with plenty of room to relax and work, but I actually find the club at LAS to be very small and confining with not very much in the way of the amenities.
Like I mentioned before though, the admission to all of the P-Clubs shoud be well worth the price of admission.