User interface and experience
Three of the suites (WPS Office, OnlyOffice and FreeOffice) use a modern ribbon toolbar in the various modules, aping the UI approach of Microsoft Office. The other suites (Calligra and LibreOffice) default to a traditional toolbar approach. Which one you prefer may come down to personal choice and your existing familiarity with office applications. Take note that some of the suites can switch between a traditional and a ribbon interface, even though you might have to hunt a bit to find that option.
