My unit is the GP1870F. It isn't their high end unit but a great buy with same technology as the FCV587. Though it is a 1kw capable unit, I only use a p66 600w transducer because I fish in depths less than 120' and the cone is perfect for that. The GP unit is a great buy as it has a GPS in it too. It acts as my back up gps to my Furuno TZT system. I like to have a back up GPS and like to have a separate fish finder screen. Only downside to this unit as a fish finder is that it is a widescreen format. This means that the height isn't as high as the standard screen orientation. However I fish in less than 120' so I don't need a tall fish finder and I find that the widescreen format is great for splitting screens. It does offer the ability to zoom and bottom lock (with a great white line). For about a grand, I think the unit is tough to beat, even by the new CHIRP units.
Here are a couple of shots from last Friday where we caught around 50+ striped bass.