In reply to pagoda:
Depends if they fit you, for a start. If you find one with all the space and features you need, AND it fits nicely....then yes.
All of Arcteryx kit is expensive, because it is made in Canada not the Far East. Therefore labour is expensive.
I have several pieces of Arcteryx, which are absolutely brilliant, although expensive (Jacket = £360).
I tried the packs on, and they did not fit me well. So I went for a MacPac.