My bear uses maul in his castsequence (lacerate, swipe, maul, swipe) and he never ever has rage issues. Especially with the rage generation from incoming damage. I suspect the problem with rage on ubergeared bears is the same as ubergeared warriors in lowbie instances: not enough incoming damage to generate rage so you only get it from hits, thus the "spam cleave/swipe" advice.

I could be wrong and my bear is only sitting at about 3200 gearscore.