The similarity probably depends upon how up to date the A320 software is that you are using.
To my knowledge, the A320 uses both Legacy (ie older) and Pegasus (more modern) software. I can't speak for the A340, but the only A330's I had experience with, only had Pegasus - with various "bells and whistles" appropriate to ETOPS. (Nearest a/p's, ETP's etc)
One of the clues to check which version you are using is to look at the DATA page. If there is only one, it is Legacy; if two: Pegasus.
At the end of the day, it won't matter too much if you are playing with the older version - a bit of button pressing on a longish flight will cure any shortcomings you may have!