Does anyone have any experience with companies that handle locally?

Ownwell is a good company. Good communication and customer service. They make it easy. But they are playing a numbers game and might settle easier than you might. Don't expect them to fight for large adjustments.

I haven't fought one in CS personally but Ownwell did on my behalf last year and I was pleasantly surprised with their ability to get it down. Letting them handle it again this year.

The market value that they have for my house is waaaaaaaaay off. However, due to the 10% rule, my appraised value is pretty close in my opinion. Should I even worry about protesting this year, or just wait until they try to raise it next year?

I'd protest if it were me. At the very least I'd let ownwell. If you don't fight it, next year the market rate will be as high or higher. If you fight it this year, it has the potential to delay future increases. Not to mention if you somehow get it lower than the 10% increase by some miracle, you save money this year. Ownwell is interesting because it costs you nothing upfront. They charge 25% of the savings they achieve for you.