I strongly disagree.
For me, installation was seamless and posed no difficulty whatsoever, and I am finding the new tool to be a highly useful and powerful addition. Have not yet experienced so much as a hiccup (installation wise) related to Melodyne in Mixcraft.
(Otherwise, here's something maybe. The auto scroll function seems to not work as expected. Minor bug, don't know if its Mixcraft or Melodyne- we'll see.)
The only reason I might consider upgrading (Melodyne) in the future is to get even more features enabled in what I am finding to be an amazing product.