A spell checker is a tool...nothing more. You get out of it what you put in..(or what the author put in as 'default').....I find them very useful in my email program, as I am a two-finger dyslexic typist, and it highlights most mistakes immediately.....I 'can' spell & proofread pretty well, but some kittle (see!) things slip by when I'm looking at the keyboard....and with Mudcat, I usually see the misteak (see!) in the 2 second pause after I hit 'submit'...arrrgghhh!...
now, if they'd just invent a context editor/checker that would warn me when I type 'tow' instead of 'two'...etc... or those embarrassing times when you misspell 'hard disk'...*grin*