I have also seen and played with the GP1870F at a boat show and I really liked it. Remember, it's a combination plotter/sounder so the screen will be horizontal as with all combination units by all manufacturers. You really cannot compare (in any fairness) the controls of a multifunction unit with that of a stand alone unit like the FCV627 or 587. A combination unit is a compromise for both dash space and budget so controls are cleverly lay out to give the user best access to most commonly used features. With the GP1870F Furuno has a unit that easily fits into both budget and space yet still with the great features AND better still performance that you will get in individual sand alone Furuno equipment. If dash space ad budget is not an issue then I agre with abbor, just buy one of each
The "box" is a diplexer box (MB1100) which is required when connecting two seperate transducers (a 50khz and a 200khz). If you intend to use the "standard" transom mount 1kW or 600W (with 10 pin plug) transducer then you do not need the box.