Using HUD

Is it essentially akin to using a performance enhancing drug?

what's the morality of using one?

Noob question perhaps, but still.

Thanks

they're perfectly legal .
They are great for spotting leaks., in your game. and good for reads on opponents.

search the FTR site , there are lots of posts on this subject

I would say its akin to taking notes at the table.

It doesn't give you any information you don't already have; it just helps you to record, organise and remember that information.