In the interest of full disclosure, I'm a member of Cannon's Pro-Staff which makes me a bit biased, but here's my honest take:
I've run Penn's, Scotty's and Cannons... and run all of them for several years.
Penn is basically out of the 'rigger market now and Scotty makes a good product.
In my personal experience, Cannon is a superior product. Cannons have the capability to do more for you and do so dependably.
When Minn Kota and Cannon teamed up, it was a huge win for Cannon.
Instead of a simple on/off switching of a high speed motor which can be problematic, Cannons step through 5 speeds so the ball starts -and stops- quite smoothly which makes life a lot easier on the end of your cable.
When you take a good look at what's available in a Cannon, you'll see an American-made, feature-filled product that deserves serious consideration from anyone looking to install a top-quality downrigger on their boat