The advantage of very high Dex is nice, but rather minor. I believe Dex has diminishing returns. I didn't have the problem with enemies standing up before I can attack again.
But I do debuff them and crit very often with my Barbarian.
+10 Dex is +30% rate of attack, so it's equivalent to +30% DPS and crit rate. This is pretty big number that stacks multiplicatively with all other sources of DPS and crit chance. Not a whole lot of things in this game can offer you that.
Not really, as there are caps how low you can go, as Parabalus explained. Once you hit 0 Recovery (doable with 3 Dex while dual-wielding), the attacks speed benefits are very minor.
Yes. But perhaps more important is that with some buffs/debuffs/cc, the Barb can quite easily top enemy defenses by over 40 points and upgrade most hits to crits in an aoe.
Well, yeah, however if you already have quite so big of a discrepancy, chances are the battle is already won and all you're doing is just clean up. Not much point in stunlocking then. If you already have -20 -30 debuff on enemy defense, stun will not add much to that, nor will prone, and all that matters at this point is DPS.
Lowering enemy defense is a great bonus, but I primarily knock them prone so that they cannot hurt my party and/or advance behind my frontliners.
Not much is needed to get that low. Devotions of the Faithful is already +20 Accuracy (also an armor debuff, but not very practical due to limited range), Cipher Phantom Forces gives every enemy in a huge radius -10 Deflection and lasts very long, till the end of most fights. Then there is Painful Interdiction, which Weakens enemies in a huge radius (particurarly good for Brute Force Barbarians, who target Fortitude instead of Deflection). Doesn't last that long, though. Of course, there's also a ton of other stuff, like Blind, Paralyze, Stuck, Stun, but these are not essential. And in most cases, either the duration or the radius isn't great. But with some you can even bring the gap to 60 points advantage.
And DPS? DPS is good, as you're typically hitting (and disabling) at least 3 enemies at the same time. 5 isn't uncommon.
You need to stack those speed bonuses: Barbarian Frenzy is +25%, Gloves of Swift Action are +20%, Durgan Steel reduces weapon and armor by... 15% each?
Dual weapons reach 0 recovery very fast and easy. Can also dump Dex and leave it at 3. Two handers need more time/effort, but can get there as well. Or near enough that it hardly matters. At that point both dual weapons and two-handers have the same attack rate. Light armor helps a lot, so does drinking a DAoM potion. Of course dual weapons tend to still win in full attack abilities (both hands strike in quick succession), which are the specialty of the Rogue.
I wasn't talking about time limited abilities, just natural recovery. Of course it's easier to get to the limit if you use abilities and potions, but those have opportunity costs, resource costs etc. Frenzy will not last throughout an average fight, so it's not really correct to assume you always have it.
Frenzy will last 80% of the time if you use Sanguine Plate. Of course, it's not light, so there is a cost to that. Another option could be to use Spelltongue - if you're dual wielding. Besides making your buffs last, that's another +15% Speed which stacks with everything.
The most dangerous enemies tend to be casters. There's often more of them. They nearly never resist knockdown and with a high Int Barbarian you can often either lockdown a whole group or keep the melee front line, while still reaching the casters behind the melees with carnage aoe.
I don't know, I can't remember many difficult fights in which casters where anywhere near enough clumped up to be effectively hit by carnage, let alone directly from behind the front line. Going back to that Concelhaut fight: the guy is way back there, and there's a bunch of flying skull casters far on the sides. I can't see how you stunlock more than a couple of them with a barbarian. And most likely it will be just one guy. And if that guy is Conselhaut you're not going to have that easy of a time stacking up all the debuffs before you can actually start critting him. A rogue on the other hand just teleports right in, hits him with a blinding strike, and then the guy never gets to do anything until he dies.
Sometimes the casters are bunched together, but often not, true. Concelhaut was a special case though. Tough sucker. But that fight isn't really representative. Strong singular enemies are probably 1% of the combat encounters, most are mobs. Potentially dangerous mobs, like the Lagufueth.
And I disagree that's just "another source of aoe". Other sources are typically somewhat limited, meanwhile a Barbarian can fight all day and night. And with high Int each his attack will be a large aoe.