I had a Korg M50 earlier which I used for a few years and after being extremely satisfied by that one I decided to buy it's successor the Krome. The Krome is very similar to the M50 in terms of usage and UI. But where it fares better is the sound quality. The sound is more crisp and natural and the samples provided are better with more variation.
This is a very powerful workstation and the capabilities are yet to be fully utilized by me. But so far, I feel the upgrade is definitely worth it, after nine months of use.
The service from Thomann has been excellent. The keyboard was delivered quickly and in the best of packaging it could get.