I use it and it's very helpful for people going the Whisperknife/Executioner route (best for PVE with big parties runs).
Best, in your opinion? But the numbers show otherwise.
I was Wk/Exec for all of my time in M5 and for leveling in M6. I can tell you that with SoD being nerfed that combo is not as productive as MI/Exec in PvE. Something as simple as changing the Path makes a huge difference in damage output. I say that about MI/Exec because I have seen them dish out 40m+ damage during a eSoT and KR. Easily besting some CWs and all SWs in the runs.
To answer the question... Recovery and other Feats will help increase Stealth regen.
Atwil "At" - Tiefling TR / Saardush - Black Dragonborn GWF / White - Tiefling OP
It applies to stamina regen, and then indirectly to stealth through 5/5 Twilight Adept. But to reach the point where I have unlimited Stealth, I stacked 74% stamina regen from all sources, 30% faster stealth regen, and 125% max stamina. I'm not Saboteur.