The Dragonfly fishfinder is very powerful; this is because it uses an entire spectrum of frequencies both high and low and creates absolute clarity.
While both of them use dual channel CHIRP sonar for imaging, Dragonfly with Navionics gold displays images on a 5.7 inch screen while dragonfly fishfinder 7 displays images on 7 inch screen (The name speaks for itself).
Most of the key features of both fishfinders are almost the same apart from a few variances. The Dragonfly fishfinder with Navionics gold however is much lighter as it weighs 4.6 pounds while weighs 5 pounds. This in part is due to the larger sized screen.
The Dragonfly fishfinder uses a two channel transducer which is a bit huge and works perfectly well. It is quite resilient and will continue working even after banging several times. It is a transom mount transducer.