I picked up MSN582x, and it came with the option.
You get what you pay for down in Toulouse - we got some slow old model MCDU's, raised keyboard vs sinked.. (were probably cheaper)!
I rather like it, since the increased G limit allows you to climb at optimum at Greendot in cases where you have steep gradients on SID's without sitting looking at the speed decreasing because the wind changed 2 degrees...
Why not use it.. Is it like those places with BS-cadet friendly SOP's where youre not allowed to use V/S either?
If Airbus didn't want you to use it, they haven't put the button there. We are still pilots (well most of us) And if it really goes haywire and end up in TOGA, it probably had done it too, since the autopilot is 15% slower when you're flying at GD + 5-10 knots.. We had one guy fly into VMO, on autopilot (and they didn't use the EXPED button - but they probably should have though...)