Experience with OnlyOffice's desktop editors?

[Dr Rainer Woitok]

Greetings,

having several "*.xlsx" files  I need to maintain  on both,  Windows and
Ubuntu I'm rather fed up  with LibreOffice's inability  to open even the
simplest spreadsheet created with Microsoft's Excel.   Searching the web
I stumbled accross OnlyOffice's "desktopeditors" binary.

Does anybody have any experience with this program?

Sincerely,
  Rainer