BM was for a short time period viable for raiding because the pet had a bug which made it benefit too much from the hunters AP. These days BM was the best damage dealer of the raid and the pet dealed 60-80% of the dmg. So in fact just the pet alone out damaged most other damage dealers of the raid. XD
In addition to that the raptor had a bug where http://wotlk.cavernoftime.com/spell=53582 was reapplied on every auto attack which made it the best pet in terms of DPS.
In my observations BM is about 10-15% below ArP hard capped MM in terms of DPS. As far as most of MM hunters (about 75%) are not geared properly, cause they are stacking ArP while they are far away from hard cap, istead of stacking Agility, a properly geared BM can easily blow them out.
Soft ArP capped MM isn't better than BM in any terms!!!