You will like the JD 4230 other than being cold natured. 1) The wet clutch is much better. Especially for loader work. 2) The hydraulic charge pump runs all the time so if you are creeping with the clutch pedal the hydraulics stay full flow. Your JD 4320 will run out of oil if the clutch is held down.
You will miss the smooth running engine/turbo that the JD 4320 has but all in all the JD 4320 is a better tractor for using a loader on.