My Z1's reverb sounded fine but the effects implementation sucked big time. This is where Korg really failed with the Z1: They added some decent effect types but didn't allow you to use different effects on different programs in a multi. If you put a flanger on a synth lead then your brass or guitar also had flanger! Agghhhhh. There was also no dynamic voice allocation so you had to manually set the amount of voices for each part aggghhhh. I used the Z1 as a performance synth for 1 sound at a time after I realised how limiting it was as a multi-timbral synth. I also didn't like the amount of delay when changing sounds.
However, these limitations were put to the side when actually playing this awesome sounding synth. It's analog modelling allowed the Z1 to emulate so many vintage synths out there. I loved the trumpet and sax programs (when played using the correct controllers of course). Some of the guitar programs were also outstanding if played thinking the way a guitarist would play. I used the stock steel and nylon string guitars for a number of gigs and got some great responses from the audience when I layered these sounds with the actual guitarist in the band! The Z1 also had some amazing synthetic choir programs.
I wish that Korg would be able to add those brass, woodwind and bowed string oscillator modes found in the Z1 to the Kronos. I heard that the programmer who developed the Z1 oscillator models died (unfortunately) and that he took the programming secrets of the Z1 oscillator structures to the grave with him.
I'd like to buy another Z1 down the track (even though they're getting on a bit now in terms of age and could be unreliable?)
The real time controls available on the Z1 were fantastic (especially that X/Y touchpad). The 61 note keyboard action was also a joy to play.
Oh goodness... I've gone right off topic. Where were we???? Oh yeah... skip the idea of buying a M3 and Nord and get a KRONOS!!!!

MIDITEK MUSIC PRODUCTION RECORDING & TUITION- albums, demos, jingles. Recording, arranging & mixing.