"PROS:
Generally, I really like my KitchenAid mixer. I took a cake decorating class last year and it was invaluable for mixing large amounts of heavy powdered-sugar frosting. (This would have been VERY messy had I had to do it by hand--with the stand mixer, just drape a cloth over the mixer and let it do its job!). I also love it for things like homemade marshmallows (which require ~10 min of beating).
CONS:
*It is very heavy and our house doesn't have a ton of counter space, so lugging it out is kind of a hassle.
*Also, it should not replace your hand-held mixer, which is more convenient and easier to clean up after.
*You're not supposed to wash the bowl and attachments in the dishwasher.
*It's awkward to scrape the sides of the bowl because of how deep it is and the mixing attachment placement, and it is not uncommon that unmixed food gets stuck near the bottom and doesn't get incorporated into the mix.
*Finally, it warns against using it to make "heavy dough" because the motor might burn out. That warning has made me nervous to use it for bread, because I'm not sure how "heavy" is too heavy for this $300 investment."