I have a Kubota ballast box and thought it was a PITA on my 2380.  It served basically only one function, and wasn't easily quick hitch compatible, I'd fill it with dirt, rocks, sand, or similar then it was a pain to empty. I recently switched to Heavy Hitch with eight forty pound suitcase weights.  It cost more but I am able to use it for various other things.  Hauling my trash cans, towing my jet ski, skidding logs (I use a chain from the draw bar mount to prevent it from rising any further than I want it), and it easily works with my QH15.  I wish the dealer I bought my tractor from knew about them as it would've saved me money overall.