I find the K10 to have a tad too much emphasis on the upper midrange, and the Katana has brought that down to a level that I prefer. It is very present mind you, just less in your face than how the K10 presents it.
The highs are also more present than on the K10, better extension, but I would still put them on the slightly gentler side as of now. I have to try them out with more songs to give a more definite answer.
The bass is decreased from the K10, but its still very present, present enough to feel that sub bass rumble, and with enough energy to give a nice impact. I won't say it's the hardest hitting, but its adequate.
Soundstage and imaging are noticeably improved over the K10, with a less forward presentation.