I'll say that I've run both Kavita and Calibre+Calibre-Web. I've stuck with running Calibreand Calibre Web together. Kavita was great but since I read on kindle and Kavita-email never worked for me I went back to Calibre. I also prefer calibre since it lets me convert files and change the cover images.

Personally I had more issues getting kavita to work the way I wanted than I did with calibre.