Well Artaher, I just bought the kn6500 2 weeks ago and have used it a lot so far! It is very user friendly, most so than any yamaha, or any other keyboard out there for that matter. There are 156 buttons and controls on the thing! That means no flipping through menus! One thing I dont like about the yamaha is flipping thru menus! and I hate to correct mike but there is a mic input and harmonizer on the kn6500. you can convert styles to it from yamaha and other styles. So I wouldn't worry about that. One great thing I look for is sound. And a real important thing to me is how long will it take me to sequence a tune. the 6500 is quick and easy and the yamaha are slow and tedius, with all sorts of backspacing and searching thru menus! I can write a style in minutes on the 6500. I used to own a psr 730 and it was a pain in the ass. the newer and pro models are no better. yamaha really screwed up on that. The sounds on the 6500 are great. and so easy to edit and save.the best thing i like about the 6500 is the set up of the buttons. Not only are the over 150 of them but they are placed in the best arrangement I ever seen.The 6500 is also upgradable. You can copy from place to place and cut and paste on the 6500 also. One thing the 6500 also has I never saw is a tracking ball to control the souns as you play.Thats really cool. You can assign different parameters to the ball too! The 6500 also has drawbar organs! Awesome! With drawbar sliders on the huge display window! I paid 2900.00 for it and am not sorry. The thing is, it is easy to navigate and change as you play and in between songs. That is worth the extra cost to me. Think of all the time and frustration I will save over the years! I alsmost bought the yamaha 9000pro before I seen the 6500. Im glad I didnt. Sounds are better too! One cool thing about the 6500 too is that the display window is programable. Meaning you can have it change back to the last or narmal window after you select a different sound or parameter in how many seconds you want it too or hit the hold button for it to stay there. Or have it not change. It has a homepage and you can choose a picture to load into it and change the arrangement of the order of things displayed in it. Great machine!!!!!!!!!!!!!!!!!! So many things and menus are customizable. How will it act when commands are given? It all up to you!
Tony