MIyajima is a very differerent sounding cartridge from Kai. It won't have the same kind of smoothness of Ikeda but it is a very exciting sounding cartridge, big bold sound but not edgy or aggressive. I heard the Kansui several times with Reed and Thales arm. I have the Zero on my VPI arm currently.
Yes, listening to Q7 was incredible. Wish I did not listen to it. Not only the price is prohibitive at this time, its weight would push my apartment's floor to the limit as far as weight consideration as well. I would hate to wake up one day and find Q7 in my downstair neighbor's living room :)
My Magico dealer also prefer Q3 over Q5 for what its worth. Nowadays, I prefer 90+ dB sensitivity speakers. I love the way those speakers going from ppp to fff so effortlessly and naturally. Listening to Q7 with the trade mark magico sound doing something likely that is amazing. I am not sure if you can ever get that with Q5 regardless of amplifiers. Q3 also does not quite do that but Eventus gives me a little glimpse of that for now :)