I have a swing arm at the console and a ball mount on the bow. Overall, I'd probably say that the swing arm is sturdier. The only reason I'd put a ball mount on the console is if you need to be able to quickly turn it around so that you can see it on the bow. To turn the swing arm around, mine has 3 adjustments that have to be made to be able to see it on the bow. These three are the two bolts on the swing arm, plus having to tilt the fish finder with the screws that mount it to the swing arm.
With the ball mount, just the one lever would need to be adjusted.
If you're not going to need to see the Helix 10 from the bow, it's a no-brainer to me, go with the swing arm.