Invisibility Sprint on vampire is more reliable as well, but as for cloak's combat viability.... You better hope your target doesn't have reveal abilities slotted. Flare, Magelight, and Skilled Tracker are insanely good right now with their range increase and more rapid revealing.
In short, new cloak is a collosal nerf for NB 1vXers. It's a massive buff against you if you're a skilled player fighting against a NB. And it's a major nerf if you're a beginner player fighting a NB. In other words: exactly the opposite of what should be done if you want to reward skilful play.
Why do I say this? Direct damage attacks take you out of stealth. Now, all you need to break cloak is a staff heavy attack. That's it. Hold down the mouse button = no stealth.
It means that attacking a group when outnumbered (thematically, the meat and drink of the NB class) is virtually impossible as someone in the target group will always have a staff and always hold down heavy attack.
Second, as a NB, there was nothing more impressive than fighting a skilled player who was good at predicting your moves. LoS around a rock and your opponent knows which path you probably took and threw caltrops or shalks down to pull you out of stealth? That was very cool to see.
Now, caltrops do nothing to a NB in cloak. Even though caltrops are there as an anti-infiltration defence and basically exist to prevent easy sneak attacks. Again: zos are thematically living in backwards world.