I was impressed enough that at Christmas I gave a number of them out as stocking stuffers and secret Santa gifts.
Connecting it to your iPhone app is dead simple and using the app to find the lost item attached to the phone is also easy. I would say that if your tile is buried in a wife's very full purse, it is very hard to hear it ring until you are really close, but the in and out of blutooth range helps you triangulate the location quickly just by walking around the house with the phone. This method is less effective if the lost item is actually in your car, but knowing that is a location to check again reduces the required time to locate items.
The best example of a real world lost item recovered happened a few weeks ago when my wife dropped her keys between a hotel and her first rest stop while returning from a volleyball tournament. The app kept showing the keys as lost, but once another phone with the Tile app came into range of the keys, a location was sent to my phone and were able to physical redirect our look and find the keys.
We have been using Tile on every pair of car keys in the house and have even experimented with it in wallets that are often misplaced between purse changes.
While I would love to see a smaller footprint, a louder noise generator, and the ability to pair to more than 2 phones, I would highly recommend the device to anyone who is prone to lose spare car keys, mail keys or house keys.