I bought my TD last spring for $118 shipped and saw the X4D yesterday for $700 which they said they would take $680 for it. I ended up purchasing a used sub troll 900 with 200' of new cable for $200. Just can't understand this set up, "not complete". I have an android phone and a tablet. Running the app would give you a max of 2 hours of battery life. Not too mention trying to see the screen during the day. I have a Samsung tablet and it is a struggle to see the screen outside. I couldn't imagine using a cheaper tablet outside in the sun. The prices Matthew quoted are retail and very few people pay retail with the internet available. As much as anyone, I waited for this product to be released. I wanted one, not needing one. After reading all the input from here and the other sites, I will pass.