Yamaha, Ketron, Korg, Farfisa(yes, FARFISA) all have mic inputs that put the kn series to shame. I have no allegience to any of these companies. I only want them to serve ME as a performer. I use what works best. The mic input in the kn series is adequate at best. It's not up to par with any of the brands I mentioned. As for the harmonies - Ketron and Yamaha seem to work the best for a built in unit, with the Korg following, and the Farfisa in the "horrible" column. Funny, how such a good mic input can be paired up with such a sub-standard harmonizer.
If you like the sound in the kn, then by all means ...... enjoy it, but you asked for opinions on this matter, and you got 'em.
I'm sure most singers will aggree with me when I say that the on board unit in the kn series is nothing to brag about.
The keyboard has lots of things to shout about, but the vocal section is not one of them.
I got plenty of sleep last night, BTW Doug.