I have a bucketload of love for my Super 5. Sounds, looks and feels beautiful. Haven’t played a Super 4 or a KZ4 but I have played a Saratoga 4 which has the same neck. It’s possibly the nicest 4 string neck I’ve played. The asymmetry really is lovely in the hand.
I compared the Super 5 to the Andrew Gouché Kingston and the stock tone of the Super just felt meatier to me, which I preferred. The coil switching on the Super’s humbuckers means you get much more variety than on the KZ and AG. Of course, more options doesn’t necessarily mean “better” but I love it.
The Kingstons are all very solid - whichever one you go for you’ll be getting a really well put together instrument.