Forget Fistbeard Beardfist, these guys are the true masters of murdering people with facial hair. Except they aren't, and it's more like facial tentacles, but I'm willing to ignore that.
What do this devil's 6 outsider RHD get you? Decent physical stats and standard devil resistances are the first things that come to mind, but there's more.
Infernal Wound is an interesting twist on bleed damage, but in the end it's just a few extra points of damage over the course of an encounter. The devil's beard is nearly worthless: you don't want to attack with your claws, and even if you do the extra damage is negligible and the disease worthless.
Battle Frenzy has a reasonably good effect on its own, but it sadly doesn't work with one of the many rage-enhancers this game has. That's too bad: it might've been worth boosting otherwise.
Finally, there's greater teleport at-will and a summon. Not great.
I can't help but feel a reasonably optimized orc barbarian 6 will already be outdamaging a bearded devil, and apart from that the devil only has greater teleport at-will and defensive bonuses going for it. With a proper tier 3 character even stronger than the barbarian, I think +0 LA is fitting.
Feedback has never ceased to be appreciated.