If you need something because you don't want to run aground in shallow water, you need a flasher.
A flasher gives you a quicker reading of the bottom if you have to travel at 60mph. It's easier to read as well, gotta watch where you're going when traveling that fast.
(sorry, didn't know link was so big)
The Matrix 10 claims to read the depth at 70 mph. It's possible, but I think it would have to optimum conditions as well as where you mount your transducer and how level your boat is while under power.
I lose my signal at about 20mph. My transducer is transom mounted and I get airbubbles which create a false reading. My reading is also delayed by about 2 sec, which makes a difference of about 633,600 feet when traveling at 60MPH.
The Matrix 10 also states a cone angle of 24 degrees which I think is pretty good.
That will explain the importance of a wide cone angle while fishing in shallower waters.
I fish in the pacific ocean, usually Monterey bay. I had a Furuno on a 19' aluminum for about 15 years which worked great. Probably still working. When we changed boats 8 years ago the first thing we did was change fishfinders to a Furuno. Some parts of the Monterey bay are over 1K deep but I really don't want to fish that far down or have enough line to get there. The first 300 feet is good enough for me.
Oh, the Furuno worked great for bass too while dropshotting or spooning for bass.
I think you have a good unit. Maybe the guys that tell you it sucks are jealous?
edit: fixed that monster link above