The stock tires are fine, no need in my mind to change until wearing them out, but I was very impressed by the Maxxis tires and how much more traction and smoother riding they were. I had some wear on the stockers before changing but I just had to pull the trigger. In my opinion, there is no better DRIVING UTV on the market than the one you have. For my personal use, I traded into a different brand, but it was not due to any dissatisfaction. I thought the Ranger had some really nice ergonomics and the add-on's, such as the windscreen, Lock-n-Ride system, cab, etc., were really well-done. Polaris has done a really good job in my opinion evolving its machines to keep on the performance edge and make them comfortable and easy to use. I also really like the larger fuel tank and storage they have. Much better than most on the market. I know you will like the cab once the doors have been added, and I would keep those tires/wheels in mind too.
John M