Which means deciding what an acceptable QoS is for those peak times - many of us think they decided too low - I personally think you should be able to get between 1/3 and 2/3rds (ideally around half) of 'peak' speeds on a sustained level at any time for any amount of time.

It's just like the telephone network of yore, no single trunk was ever capacitied to mothers day call traffic - there were reroutes, and more than one path to any large point, so you'd get a lower quality of service, but the traffic would still get thru.