My Kawai MP11 fits nicely in the bag. It has a little bit of leeway, but it's not a big problem. Just fill it with socks or something if you are worried.
I was afraid a little bit when the bag arrived - The cardboard box that Thomann used for the delivery was shorter than the actual bag, so they folded the bag at one end. There were some creases left for a while, but it seems the bag was not really damaged by the fold.