So I switch back and forth between my robot and Polaris and each of them have some cons. The Polaris is always needing a small tweak to run optimally (or needing a part replaced). There's only a few things you can adjust assuming it's new and all the parts are good. Play with the way the back jet is positioned, most people say 11 oclock works best for them, but you may need to try a few different settings. You can also adjust how far back the float head sits and that can make a big difference. I suggest studying it and see what exactly it's doing. Climbing too much or not enough? Suspended in the water? Popping a wheely?
I've only had my pool for about a year, so maybe one day I'll figure out how to use the Polaris it requires less tweaking, but I ain't there yet. I'm still adjusting mine all the time trying to find the most optimal settings.
The robot is much lower maintenance from that aspect, but it's major con is that it doesn't do all that well at picking up big leaves and debris (but does an excellent job at the small particular type stuff).
