I listened to both the Katana and Encore at the time of purchase though to be frank, I didn’t spend as much time with the Katana as I would have wanted. Someone else here who owns both models could maybe answer your question better. Also I have not listened to your AK70MKii. But.......in my uses the Encore IEM is great for classic rock music, pop and 90s music. For some tastes they may be missing a little low-end for rap? But with classic rock they add a nice warm crunch to the guitar. It’s like the guitar has a glow. Most importantly all the instruments used in classic rock sound exactly as they should. Nothing comes off as out of place or forced. Also for live classic rock and hard rock recordings there is a special connection placement of instruments and vocals which seems amazingly natural and real. There was a couple of my live albums that sounded as if I was actually on stage; never experienced anything like it? In fact don’t be surprised if you revisit all you old classic rock recordings and find little details which were always there but never heard. Many of my favorite songs seemed more detailed than I thought they were. Cheers!