Hm... let's see. I hope I can figure out the maths...
I'll compare the stats based on the ranger/warshaper i have in my campaign
At Lvl 20 he'd have +6 Str bonus and a +4 enhancement bonus, he'll use his natural attack for 1d8 dmg
hit chance vs Lvl 20 between 35-50% without boni (depending on monster type), I'll take the 50% chance because it's easier on the math

so actual dmg values should be far below.
different options:
• 6 attacks, distributable in close burst 2, base damage 1[w], + Str per additional hit
single target:
4,5 weapon average, +4 enhancement + max 5 additional hits at flat +6 (str)
average dmg: about 23-24, max 38-39
added option of distributing dmg on multiple enemies, this actually increases the damage output the more enemies are available
6 targets (unlikely, except for hordes of minions....):
4,5 weapon average, +4 enhancement
average dmg total: 25 max dmg: 51 (8-9 average on a single target, max 12)
• 6 attacks, distributable in close burst 2, base damage Str, + 1[w] per additional hit
single target:
+6 Str, +4 enhancement, + max 5 add. hits at 4,5 average
average dmg: 20-21, max dmg: 50
6 targets:
average dmg total: 30 max dmg 60(!)... still, unlikely to have that many targets available, and it would be only a fixed 10 per target....
• Wis based is far to weak for the heavy-hitter power rage of claws is supposed to be
• Comparison: shadow assassins final blade as max [w] striker power of that lvl, has a prerequisite (target bloodied) and an edditional effect (shift).
Average of a 5[W] power: 32,5 max max 50
Nearly all high-dmg dailies have a Miss: effect
• Comparison: Area effects of lvl 20 generally have 3 damage dice
let's say 3d8..
Average (single target): 23-24, max dmg (single target): 34 dmg
scaling upward, the more targets, the merrier.
Cold steel hurricane has similar dmg values, but gives a healing surge...
Thoughts:
- the +Str scales better on higher lvls, and I like the numbers better than the +[w] per attack ones
- math aside, it is more enjoyable to do additional [w] of damage, it causes more suspense

- the variability of having 6 attacks probably evens out the neccessity of a Miss: effect
- no matter what version, the area dmg isn't very high compared to other multiple hit powers (battlefield archer's quarry's bane, for example). I might want to increase the dmg against single enemies.
- Maybe give a limt to Rage of Claws' usability. Make it usable when bloodied, also gives additional flavour.
- There are no pure dmg powers, they all have a secondary efect.
- Maybe enhance the area effect portion by inflicting a condition...
- Or add a utility effect like shifting...
Hm....Let's see:
RAGE OF CLAWS
Daily • Standard Action • Martial, Weapon, Polymorph
Special: You need to be bloodied to use this power.
Close: Burst 2
Target: 1 to 6 creatures
Attack: Str vs. AC, 6 attacks
Hit: 1[W]+Str against each target, each additional hit gives a + Str Mod damage bonus.
Effect: The target is knocked prone.
Comments? (I don't know if my math is right... it's been a long time since I actually needed probability math *g*)