I'm running a claws/regen and am now at lvl39. I have found that stamina and health has helped me and really reduced my downtime but I don't think that it is needed.
My opinion, it's really useful especially if your running toggles like tough and focus accuracy.
No need for stamina, although if you want to run focused accuracy (from body mastery epic) a lot, it is helpful.
Is it needed? No. Is it useful? Definately.
With Stamina there is no need to slot any end reducers (except in Focussed Accuracy), enabling you to slot your attacks with an extra recharge or accuracy which is definately worth it, in my opinion.
Is there any character that doesn't need Stamina, sigh? 
On my Spines/Regen I found that in the early levels ( 1-20 ) stamina really wasn't missed. I think I got it at level 24 when I was levelling up, just in time for IH which at the time was a very expensive toggle. I believe claws is cheaper than spines.
Regen is light on endurance ( only have integration toggle wise ) and QR is better than stamina so in theory you shouldn't need it. I certainly wouldn't worry about getting the fitness pool in the 12-20 level range.
However if you intend to get Focussed Accuracy ( which I'm not sure you really need given Follow Up in claws has a to hit buff ) then you need to have stamina 3 slotted before you hit the 40s. Focussed Accuracy allowed me to increase the recharge on my attacks which was essential, claws has a much tighter attack chain so you may not need this.
@Unthing ... Mostly on Union.
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Is there any character that doesn't need Stamina, sigh?
[/ QUOTE ]DM/Elec brute temed with a kin 
Have a lvl 12 claws/regen and would like opinions on whether stamina is needed or a nice to have as regen has QR.
Altitus doesnt have a cure just more alts