The landscape along the K-K track is great, being much better than 6 foot track and one of the best in Blue mountains/Kanangra Boyd region.
It would be very enjoyable if walking for 3 or 4 days and you would never think back 6 foot track again as it is 6 foot fire track other than natural one.
For experienced walker(s), K-K track could be done for about 11-12 hours in one day. But there are many potential closure or flood on the track, additional time may need.