I changed over to the US version a few years ago and for the most part its fine. I have to re-jig playlists occasionally, I normally find if a song comes up as unavailable its still on Spotify but just released on a different label and you just find it and replace it.
A few artists have “Non UK” versions of albums, Portishead - Dummy is one. If the mood takes me and I want to relive the mid 90’s glory days of Brit pop… I find that some bands are missing large chunks of their discographies… Primal Scream, Super Furries. Most of which I have downloaded any how… its just convenient to have it in one place.