When I recently converted to my Airbus, during Sim LOFT training the exercise included a scenario where we had to G/A off an approach, enter holding, and estimate our time to diversion. Straightforward stuff.
But when I used my old iron dial pilots brain to do the numbers the instructor quite rightly pointed out that the FMS would do all that for me. I suggested I'd usually to do my own gross error check anyhow as a matter of course, especially given what had just happened to Hapag that same month.
His answer was he knew nothing about the Hapag incident, and just forget about wasting time with mental arithmetic...trust the FMS.
Naturally I still do my mental arithmetic.
