I'm an extremely good speller and tend to have good grammar, and in general I prefer to write and read complete sentences.  I believe I tend to notice bad grammar and it gives me pause.

BUT! I don't want to be a snob about it.  I actually think it's interesting that many of my smart friends are bad spellers or poor grammarians. In personal communications, I've become pretty inured to the indignities some people visit on our language when writing it down.

That being said, I am always distressed when I'm working with an organization and their press releases or constituent emails have typos or bad grammar in them, and I will point it out.

Even worse is when the date, time, or location are wrong in an event announcement. ARGH! That one does drive me crazy.