I haven't but I've never had vim perform anything slower than perceptively instant. Even on the lowest of specification virtual machines and servers I've installed it on.
I'm not sure how, in my use case, neovim could improve upon vim. vim's fast, available virtually everywhere, packaged with many OS's and distros, and has a rich and active community. I'm not sure why I'd want to change.
Neovim seems like a fun project ("let's reimplement vim!") but it feels a bit redundant, like a reimplementation for the sake of doing a reimplementation. There's an intangible reason why vim is so popular and has such a following. vim is well engineered, simple, and has been well cared for over the years. If I'm integrating something so deeply into my workflow, electing it the main way I interface with my code, it's going to be the 25 year old project that's beyond reliable, has evolved conservatively and is ubiquitous. Ten years ago I was writing code in the language du jour using vim, and ten years from now I'll be working with the hot new language. In vim.
vim isn't a broken relic of the 90's, it's one of the best, most valuable tools in my toolbox.
Respectfully, given what you've said, you should look at neovim. It's not a fun project to reimplement vim, it's a fork due to vim's (i.e., Bram's) previous reluctance to advance vim with new features like async.
Since they've forked it, they've done an amazing job cleaning up the codebase, modernizing the toolchain and implementing great async support, while maintaining almost perfect compatibility with vim. They've also created a real development community where many people participate equally, not just trying to get the "bus factor of 1" commit bit holder to accept their patches.
I switched a year ago, brought all my plugins with me, and have seen only improvements in performance and features. If I had to choose which would survive for the next 30 years, it would be neovim. Thiego Arruda is the best example of an open source leader. I have a deep respect for Bram Moolenar and what he did with vim, but until neovim came along, vim was sclerotic and getting worse. It speaks well of Bram that when real competition came along, he returned to active development of vim.
Neovim is just vim improved, like vim is vi improved. It's a fork. Nobody is saying vim is a broken relic of the 90's. It is by far the most valuable tool in my box as well. The community is the same, plus some dedicated diligent people who want to improve the best editor in the world. Give it a shot!
