I know stony devils aren't exactly barbed devils, but it's the closest thing I could find a reasonable picture of.
Barbed devils are mid-ranked devils with all the regular devil traits. The chassis is definitely not bad, with good physical stats, reasonable mental stats, huge amounts of natural armor and SR, amongst other things. Medium size was a bit surprising, though.
Where many other baatezu have a Fear aura, barbed devils can instead cause fear with a successful attack. It's pretty cool, though I suppose you'll often be faced with fear-immune creatures or beings that can teleport or run away faster than you can attack.
Improved Grab is probably not worth your time. Freedom of Movement has been available a long time, and you're better off just wielding a weapon in those claws rather than trying to grab people with them. The same goes for Impale: its damage output pales in comparison to what you can do with a greatsword.
Barbed Defense deals some damage to creatures attacking you. It's reasonably useful, though large-sized (or larger) creatures wielding weapons can get around it by attacking from a distance and ranged enemies ignore it altogether.
Finally, there's the magical abilities. Greater Teleport is expectable for a fiend of this level, Hold Person is rather useless (if you want to immobilize humanoids, there's better ways by now) Major Image has lots of potential uses, and Scorching Ray is a good ranged option that outdamages Eldritch Blast but has a worse damage type. Finally, there's Unholy Blight and Order's Wrath, but they are only 1/day and don't deal that much damage anyway.
Summoning another barbed devil, or some bearded devils, is good, but the 65% chance of failure is rather annoying.
Compared to the hezrou, a fiend of equal CR, barbed devils have better physical stats, no bite attack, smaller size, slightly worse SLA's, and a less good save-or-suck ability. It would be logical to conclude their ECL should be lower, which would make +0 the only option.
Is that balanced? I am not absolutely. However, remember that the barbed devil is too small to deal great melee damage, has pretty bad SLA's, and no other abilities to exploit. I'm keeping the LA at +0 for now.