I found out there is a cap on BP timer reduction. Summoners cap at 45 seconds for BP timers.
People with full relic, YYR, and this staff can potentially with good augments get 41 seconds. I have tested this and its impossible to get. You should hope for better augments than BP delay if you have the gear to achieve the normal 46 sec Bp timer through our current gear.
There are still a lot of BPs that a Bahamut's staff is better than this for. It does not give skill, so for buff BPs the Bahamaut's staff is better. Also, I'd probably use Bahamut's for magic BPs for MACC.