Just in case you're not aware of this: A few years back I analysed a number of RTO videos and consulted flight manuals, the summary of which is available here:
http://wiki.flightgear.org/Airliner_brake_performance
Bottom line: max manual braking -- as in rejected take-off -- gets you 3-4 m/s^2 deceleration. Being able to stop from 180 kts in 700 m is 6.1 m/s^2 deceleration -- way too strong.