I own 2 Jackson Kayak's, a Big Rig and a Kraken both of which have molded transducer scupper holes made to hold the Raymarine Dragonfly transducer. I own both the Dragonfly 6 & 7 model units so I'll speak to both and any differences in them I'll mention the specific model.
While convenient to have that kind of integration, my decision to go with the Dragonfly fish finder wasn't solely based on "convenience" or that Jackson promotes that fish finder in their kayak promotions. I was looking at other notable brands, for much less money, but then I really started to notice things about the Dragonfly that fit my personality and fishing philosophy.
The Dragonfly is like the iPhone of Fish Finders.
First, the design is extremely simplistic! For me, this is a GREAT feature and here's why: You can spend more time fishing and less time screwing around with your electronics and all the buttons on it. The Dragonfly has 2 push buttons, 1 joystick knob, and THAT controls everything you need to do on the unit. You're never more than 1 button click and a joystick press away from pulling up Sonar, DownImaging, Chartplotter and the various combo's of 2 out of the 3 modes in split-screen. The sonar, downimaging, chartplotter all seem to be top notch. It's easy to see baitfish from predator fish on the sonar and even gage the sizes of fish. DownImaging is incredible how detail it is to see structure under the water. Chartplotter does just that and does it well while displaying GPS coordinates, Temp, Speed...all the basics.
Second, the screen resolution on the Dragonfly 7 is very crisp, detailed, and overall exceptional. The Dragonfly 6 has less screen resolution pixels than the 7 but I mean the differences, in all honesty, is negligible! It still looks great and is crisp as well. Both models work well in bright sunlight however, by raising the display settings, it will eat up more of your battery power so make sure you have a fully charged battery.
Speaking of batteries...
Third, I've found the Dragonfly to be pretty good on power usage! I think this can be attributed to two things: 1. Where you position/mount the Dragonfly and 2. The display settings you set it at. I like to keep my Dragonfly units positioned directly right in front of me, no more than a foot away at most, so I don't ever have to strain my eyes trying to look at it from a distance where sunlight will affect my visibility. Because I keep my units 6"-1' distance and centered, I am able to leave the display settings in the 35-50% brightness range even in bright sunlight and have plenty of battery power for my trips. I've gone 2 weekends of fishing before recharging my battery, 'nuff said.
Additionally the Dragonfly has an app! It's actually pretty cool and works as advertised. You can mirror whats on your display right onto your smartphone where you can take screenshot pics, swiping to go back over the display almost like a timeline function, plus you can do social media right from it too. The BEST use I've found for when someone else who's fishing with me doesn't have electronics on their kayak, is to have them download the free app and stream my display to them. Since we're fishing in practically the same area, they now can see what's going on below the water and fish accordingly.
...and now for the cons...
The Dragonfly units are a bit pricey compared to similar size/feature range of units from other top brands. Maybe this is a trade-off because of its design and efficient design? I mean we all pay hundreds for an iPhone when a $100 smartphone can largely do most of the same stuff. If you're not fishing offshore or really big bodies of water where you need to paddle to GPS points miles out, I'd suggest saving some money and getting a base unit without any of the bundled charts. You're really only going to really need the sonar and downimaging 90% of the time. The Dragonfly transducer is one of the larger/longer ones on the market so before buying, really know where the transducer will be mounted to or if your scupper hole can fit it!
Sidebar: Jackson Kayak owners beware! You can only fit the Dragonfly 6 or 7 transducer flush in the scupper holes. The Dragonfly 4 & 5 has a very different transducer and it will not sit flush and properly in the scupper hole.