Having your text editor corrupt the file it's working on sounds like the absolute worst case scenario.
Is this fuzzy finder thing some third-party plugin? Do you have any idea why it corrupts the files that you point it at?
A github issue about it https://github.com/junegunn/fzf/issues/206
I've kept vim installed as a fallback so I can easily use vim if I run into anything that is a show-stopper, at least until it's fixed in nvim. I still plan on submitting patches to both for the foreseeable future though.
I use it with true color support enabled, and a terminal that supports true color, and a patched version of tmux that supports true color, and finally all color schemes render as they do in gvim!
Also the terminal emulator feature is awesome.
Is it ready to download and run now with all the features?
No. Although some features are a work in progress, Neovim isn't at a stable point. Using Neovim should be done with caution as things may change.
This warning is why I haven't yet tried switching over. Are they just being overly-cautious?
[1]: http://neovim.io