This is comparatively. You need to compare it to the MM1 version:
I'm not bothering. Too many MM1 monsters were poorly designed. The purple worm comes to mind as not being nearly threatening enough for something of its level. (Mainly due to poor solo design.) I was actually going through Thunderspire Labyrinth earlier today and nearly groaning at how lame the elites were. (Mind you, there tended to be lots of monsters of levels quite a bit above PC level. Seems to me the proper solution would be to us elites of the PCs' levels.)
I am
comparing the owlbear to the new MM3 rules though. I haven't run an owlbear encounter myself (currently doing 3rd-level Dark Sun, there are no owlbears there) but I'll see if I can reflavor it and report it once the PCs are around 8th-level or so.
because the MV brute is more accurate (+2 accuracy in fact) over the MM one.
Also in the new rules.
So it's more likely to hit a target with both claws, dealing 8d6+12 damage, compared to 4d6+10.
That's what it's supposed to do.
Then the beak of course which auto hits, dealing 4d8+22, compared to 4d8+5.
Once you've been grappled. The escape DC is pathetic, being only 16. Even an untrained 8th-level character with Strength and Dex 10 will hit that DC more than half the time. In effect, it's
not auto-damage. It's anything but, with one exception (see below).
Which one after using it's dual claw attacks do you want it to action point and beak you MORE?
I'd rather get a chance to escape first

Yes, the owlbear can brutalize one PC. Dual claw, then use its sole AP to beak them. It's attacks would deal 80 damage, enough to down but not kill most 8th-level PCs. (I think even a wizard would survive.) As some people have pointed out, the new monsters do punish PCs for using bad tactics. If the owlbear (an Int 2 monster) somehow managed to jump the mage (it probably is smart enough to attack whoever is at the back, and maybe that's the mage), the party's defender should mark the owlbear and draw its attacks, giving the leader the chance to heal the mage.
I know none of my players are going to say "Yeah, we're not going to notice the difference in the MV owlbear". That was the point: Monsters at all tiers are not afraid to do ridiculous damage if they feel like it.
Also, as a brute limited power it can do up to 50% (or even 75%, depending on the author) damage.
I'm actually confused by this specific point. Were you saying MM1 monsters could do ridiculous damage (and so there's no need for new rules) or are you complaining that MM3/DSCC/MV monsters can deal ridiculous damage because they could dish out a massive amount of damage with an encounter power?
(And on that note, elites are actually kind of nerfed when it comes to dishing out heavy limited power damage, since their encounter powers only deal regular limited damage for a monster of their level. And the owlbear's encounter ability doesn't do damage at all.)
This isn't the point. Abduls point is that "Heroic MM3+ monsters are pretty similar to those in the MM". This is plainly and utterly false.
I get this point. I don't think that MM3+ monsters are similar to those in the MM1. I happen to think that's a good thing though.