I'll leave the poking of holes in this explanation to other readers of this forum.
It's the same as with the frequency memories of some NAV/COM units: By the time I have pulled the number of the memory slot under which I filed a certain frequency from my own memory, I will either have read that frequency from the approach plate or remembered the figures themselves...
But obviously, peoply base their buying decision on this kind of stuff.
BTW: I have yet to time my first apporach (after 21 years of instrument flying) - but thats a completey different topic.