@nochanging 

You will need to read up on real time wireless speed and negotiated wireless speed.  That research will help you understand what is going on here.

You will not reach full wire speed over wireless, especially with 660 and or 670.  You can widen the band, but that will cause more RF interference.  That will give you a bump in speed.

These APs are enterprise APs, they're programmed to handle high client count and stability under stress... versus a home router.