In general the CMT is fast (such is the case now for example). However, twice today when replying to a post/question and entering a message with many paragraphs and lines, text editing became very slow. After say five or so lines, each character took around a second to appear... This only seems to apply when there are a few posts before, for example it is not the case now.

I am using Windows 10 with Microsoft Edge. The computer had about 1-5% CPU usage on each occasion, so I doubt it is down to the computer. Although MS Edge could be an issue.