How so? They have enough spectrum and have been adding more backhaul. They started out early markets with 20Mbps backhaul but are now doing 100Mbps where they can get it (including my area). They say they'll be targeting 500Mbps backhaul in the future. May depend on market or site though on amount of backhaul available in the long run.
If Clear can't sustain enough to stream video, I'll switch back to TWC but I don't expect to anytime soon.