I always verify full operation before taking possession of something. Make sure the loader works as expected, as well as the backhoe. Check forward reverse, and all travel speeds. Wiggle around on the seat when moving to verify the safety switch isn't too touchy. And have the person dropping it off answer any questions you may have about it.
Check for any visible leaks. Check hose clamps on coolant lines to make sure they aren't loose. Double check fluid levels front too back. And verify that the charging system works
You may think I'm crazy about making sure the charging system works, but I've had brand new pieces of equipment shipped in with either a bad fuse, or actually missing a wire in a section of the wiring harness