I like that it has an app for my iphone, which makes life easier when working out if i'm going too fast or not! It's also very easy as you can see where your boat will be in relation with other boats around so there isn't any guess work involved at all - just set up how many seconds before contact etc are ok then get stuck into fishing!! There really aren't anything negative about this product but maybe more options would have been nice? Maybe some kind of indicator light system instead of having numbers from 1-10??