The two button press is the same on PA3x and PA600.... but who knows? Perhaps Korg will come to their senses and either put dedicated buttons for it on the PA900 (coming soon) or figure out a way to do it with a single push on a screen 'button'.

I've tried it on the PA3x, and it is, well not easy, but not impossible to mess up using a double press (you have to be extra careful to not press one button fractionally before the other), which is why I recommend the EC-5 so highly.

The other problem with button pressing is, you have to press for CS Play/Record/Stop in the bar BEFORE you need it (it starts on the next measure, kind of like asking for a Variation change) and with most popular music, that means in the transition, or 'lead-up' bar to the new section. This bar, unlike possibly many before, often contains several chord changes (a II-V, a II-V-I7 or maybe a VII-III-IVm for example) which makes timing the button press tricky. Too much to do just with your hands...

I would not dispute what you said, Diki ... my little test was done with just a four beat V7 as the lead - in chord, so I had plenty of time ... it also was not done 'in the heat of battle' ... a foot pedal assigned to this function obviously is the best choice ...