Put a Garmin Echo 550 on the boat last year. Same as you, wanted a smaller unit on the dash. Any experience with these units? Very happy with it. A friend got one after seeing it on my boat and he is happy with his. Show rigger balls beneath the boat? Yes. Marks the thermocline. Marks fish and bait very well too. Track bottom well? Yes Show fish while at speed? No but I have not played with the transducer position to try to dial this in. Or spend twice as much and get the Furuno FCV627? You cannot go wrong with a Furuno.