In my opinion,
Garmin is the most user friendly GPS made !!!
I'm not a big fan of combo units and splitting screens though, but if space is limited, go with one!
For fish finder/ bottom machines, there a better choices than Garmin
I have a simple Garmin 152 on the boat. Just a GPS not a plotter/finder. I love. Like others said very user freindly. Harly ever had to look at the manual. Does a milllion things although I just use it for a handful. Someday when I get some extra doe was thinking of getting the 192C. Like Ronnie said I personally would rather separate units but space is a factor in smaller boats.
Same set up as Blue Oyster. Garmin 178C on an 18' Parker CC. Perfect for an 18' boat. Lots of features and easy to use. If you have the extra money, get the color. Better resoultion.