[MBCook]

I would agree that Office is probably a beast to port due to its long history and large code base, but that still doest explain why it should be considered an achievement for Office to run at all on ARM. ARMs are in the same ballpark as x86, clock for clock. It's not like its a 50x performance difference.

Mythbuster's argument just isn't making sense to me.

[Mythbusters]

It's not the difference in performance but having to compile against a different architecture altogether. These two are architecturally different and porting an old legacy app like office cross platform must not be an easy feat. I don't see examples of old apps easily being ported over across platforms.