I might as well start and be the 1st shot down.............
My own experiance
However,I run two units,one up front on trolling motor and one on top of the dash (transome transducer).
Eagles are a good buy,but lasted about as long as Lowrance (its just a cheaper $ version of the Lowrance)
Humminbird has treated me right, but it depend on the specific unit,I found out you either got a good one or a bad one.
Lowrance had the best of everything but was the one's most short lived.
Garmin to me is my favorite and has been the most dependable for the buck,I especially like it with the GPS feature even tho other units have it too

Like you, all I am mainly interested in, is pixel count,bottom detail,scrolling speed and water temp. But I want it to read those details reliable, at somewhat higher speeds too.
I dont care about all that trash that shows up as fish in some glory hole and goes beep beep beep.
Had a Humminbird side scan once,mine was a piece of cra*, wasnt worth the $'s spent.

Looking forward to see replies as I am about to buy another too and am leaning strong on Garmin once again
My opinon is just that, mine.
I hope other folks dont take exception with my experiances, with any specific brands that they may own.
I didnt intend to knock any particular brand or persons choice on purpose.