I do not like the battery powered or air powered grease guns. I’ve had a dewault and one from McCormmick. Neither would prime easily. They both worked great but you’d spend an hr priming the dang thing, especially the air one.
As for John Deere lawn tractors, I’d buy them from Home Depot or Lowe’s , you’re actually getting the cheapest line they make. They’re not even really John Deere’s but Cub Cadets re-painted.
any of the L or D series, are essentially rebadged cub cadets. The only series actually made in a John Deere plant with John Deere designed parts is the commercial series