I actually quite like Valeera, but with the Feint nerf incoming I think it'll be getting a lot less use. It's quite strong in mythic+13 and higher where there's a lot of damage on fights, being able to more or less heal yourself through a boss fight is huge.
With Feint cost going up I don't think it'll be anywhere near as useful since you can't spam Feint anymore without a massive DPS loss. Valeera is one of my favorite utility legendaries, but I don't really see myself using it after the nerf. Hopefully they notice and change something about it, even just giving it something other than Haste would be fine.