With /regen, yes, with any other secondary... as long as you're not running quills it SHOULD be viable.
yep anytime after lvl20
"We're not tools of the Government or anyone else...
Fighting was the only thing, the only thing I was good at...
But atleast...I always fought for what I believed in!" (Gray Fox)
@Captain Paragon EU @Captain Paragon.
I took it at 22 on my Inv scrapper. I was ok for end - I just needed to manage my toggles a little (i.e keep unyielding turned off most of the time).
Defiant 50�s: Generalissimo, Righteous Bob, Splortch, Brutus Cayuga
Union 50's: Chimera Obscura, Diet Anthracite, Grim Proctologist, Puny Little Minion, Raging Bitumen
In Soviet Russia, mission farm you!
great, i'm a regen. 
My regen took stamina at 30 and didn't really even require it then
Defiant 50�s: Generalissimo, Righteous Bob, Splortch, Brutus Cayuga
Union 50's: Chimera Obscura, Diet Anthracite, Grim Proctologist, Puny Little Minion, Raging Bitumen
In Soviet Russia, mission farm you!
i got a claws regen and im debating stamina at all, even against elecric/end drain baddies i still have never run out of end
although i already have hurdle
it is okay to take Stami at 24... right?