Intellect. Super obviously has the highest cooldown of any of the abilities so having 100 in intellect really isn't gonna make the difference that having 100 in strength, recover (warlock) discipline, mobility (hunter) or resilience (titan) is. Orbs of power and other super regenerating mods make intellect redundant. Mobility is only really redundant if you're a Titan. If you're a Warlock, mobility makes flying around in solar so much better and Hunter speaks for itself