I have a Garmin GPSmap 178C Sounder mounted in the console of my boat.

The display on the 178C is starting to get dark spots, so it's time for a replacement.

I'd like to find a unit to fit in the same mounting hole with little modification. After looking at all of the different manufacturers, it looks like my best option is the Garmin echoMAP CHIRP 53cv.

What do ya'll think about this particular unit, as far a features, quality, ease of use and value?