My goal in the quest to improve my spelling is to get close enough to the correct spelling so that the spell checker can finish the job. I hate the "no suggestion" message and I'm working diligently to raise my game to the level that I don't see it very often.
I have to admit that poor spelling is one of the things that just bugs me no end. In my job, I have to write engineering reports all the time and the ability to make yourself understood is essential. Also, being a product of 1960's elementary school, spelling was something that was drummed into your head. Misspelling is so commonplace anymore that it's noticed less and less. Apostrophes where they shouldn't be, no punctuation, and generally poor sentence structure are things I notice daily.
"I tried hard to not loose my keys. But, I went ahead and lossed them anyway."
Spell-correct gets most misspellings. It's usage or simple English ignorance that gets through: things like apostrophes in plurals, then/than, your/you're, to/too, and my BITOG favorite, "Mobile" for Mobil.