I've had my Misto about 5 months and feel it was a good purchase. I prefer using olive oil from Spain for it's strong flavor, and can change the oil if I desire.
One reviewer said the sprayer "spurts"; I would describe it as steady and even, but definitely not a fine spray. The lid is easy to pump, and about 10-15 pumps will spray 12 muffin tins, or a griddle, or a few cookie sheets before running out of "oompf". Another reviewer said the lid "raises up on its own"...don't overpump the thing if you're only using a few squirts! If you put it away with little or no pressure inside, the lid won't push up.
I purchased mine at an exclusive kitchen store and paid $21, so the $17.99 price on Amazon.com is a good deal if you can work out free shipping. I'm planning to buy one for my Mom for Christmas, I'm sure she'll love it!
Why not 5 stars? If the price would come down to about $10, I'd give it 5 stars.