Lowrance M68C?

Does anyone have any comments on the Lowrance M68C? This is a combo
GPS/Fishfinder plus other good features. Does have an optional
speedometer for $70.

I have tried to find information but nothing yet. I did notice when
doing a search that there is an optional data cable to connect to a
computer to download maps or something. Is that really necessary to
use the GPS feature?

I will be using it on a Smoker Craft Stealth 17'. Rivers, lakes and
bays. I will be doing a bit of trolling for Trout, Kokanee, Walleye.

I have been told by one store that the color is suppose to be easier
to read. The boat dealer said the Lowrance rep made the same claim.
Some of his customers have said they perfer the gray scale while other
customers claim the color is easier to read.

If the M68C is not the right fish finder let me know what is. The
M68C lists for $400.

Thanks,
Bob