I am. My tanks are all almost stock builds, and only improved when stock parts fail, and this includes aesthetic parts which I repair/replace when I break them, with metal parts if they are available. The only items I upgrade during the initial build are ball bearings to replace bushings, and a metal gun barrel elevation arm.

You got heaps more to upgrade depending on make, and model of tank. I've seen Heng Long Tiger builds that were fantastic and fixed all the faults of the original tank, but also almost nothing of the original tank remained.