This thread stopped federating for some reason so I'll reply to myself:

How different is neo vim from regular vim?

Functionally it's pretty much identical. For the user the difference is in the added features and development model. Neovim's development model is not centralized to one person and makes real progress. Vim on the other hand is much more a pet project of its creator and seems to get new features only if it starts losing users over to Neovim. Using Vim you're always going to be behind the curve and under the whims of Bram's decisions. Neovim integrated Lua as a first-class language for configuration and it was then that Bram had to do something about vimscript, but opted instead to create a new, backwards incompatible version of vimscript, another bespoke language. I very much advocate making Neovim the norm instead.