shakeel Ahmed,

Please see response below:

Can punch in and out record works simultanously on all parts including APC
or does it record on a single track at a time
>>>AJ: Both punch in (step-by-step) and single recording features are available on the KN6000/6500. Within the sequencer mode, you can choose to record either via single tracks (one by one) or record a song using the APC (record once). The editing tools for sequencing and recording APC are extensive (include punch in, move, copy, delete ...)
Hope this helps.
I would still caution for you to try the keyboard (at any cost) prior to purchase ... unless you have some sort of return garantee - just incase! There are quiet a few to choose from out there.

AJ