At least on Linux/ubuntu.... On Windows, with my self compile hunspell,
it seemed quite fast.
Just do this test:
1) Disable inline spellchecking. Measure the time to load the User
Guide. Do it twice in order to have the file in cache.
2) Enable inline spellchecking and select "aspell" spellchecker. Measure
the time to load the User Guide.
3) Repeat with "hunspell"
I am not sure if it is spell() or suggest() that is so slow but I will
investigate. I have the feeling that the ubuntu package is not quite
optimized. Considering that no package makes use of that library, I
guess it was never reported...
Abdel.