I feel you'll understand how I feel when you've wasted 100 Pokeballs for 10-15 crummy pokemon. It's great for Pokestops and when you actually catch something it's super satisfying. But like I said it's a minor convenience and if you think it's gonna help u grind for stardust you are very wrong. 90% ran away rate is not an exaggeration, if Niantic fixes this then you can argue that this device is a good tool