I have an MZ-5N and an MZ-7, which has controls very similar to the MZ-6. I find that the "classical" style controls on the 5N make it much faster and easier to change manual speeds and +/- EV. Also, after you get used to the body, the 5N rotating tab switches for motor and metering, plus the slider for spot/matrix focus allow you set just about anything while you are looking through the finder. The MZ-7 and MZ-6 require you to change your gaze to view the LCD panel, and the single-step toggle switch around the shutter release button is a pain. If you normally use reading glasses but use the camera's diopter for the finder, then you have to put your glasses on to view the LCD panel.
OTOH, I'd really like to have some of the MZ-6 custom functions (esp. time delay with remote, and leader in/out on rewind - the only one missing is an auto-rewind on/off control). The MZ-6 high speed flash synch sounds great - I'd love to have it. The wireless flash connection to the AF360FGZ sounds cool too, but it can be counter-productive if the pre-exposure flashes between the camera's popup and the 360 cause a reaction in the subject. AFIK, the MZ-5N and -7 both work with all advanced functions on the AF360FGZ, except for wireless control and high-speed synch. I often use either the MZ-5N or -7 with the on-camera popup flash and two off camera flashes: an AF360FGZ and an AF240FT. This combo (with 5P wire connections) provides either leading or trailing curtain synch - which covers most applications that might come up. I'm sure either camera will provide excellent results; the key difference is how you shoot - if you like to change the camera settings while watching or tracking the subject, then the MZ-5N (or -3) may be the best solution. Jim www.jcolwell.ca