Ryan McAvoy said:

it looks like the actress is going to be a great character/villain, even if it's not really the proper Master character that we know from Delgado and Ainley (Simm wasn't The Master either).

Upon rewatching Dark Water, she already feels more like Delgado's Master to me than either Ainley or Simm ever did. (Beevers on audio still comes closest to Delgado, though.)

I just hope we're done with the stupid "drums" now. And I really hope they secretly shot a Simm>Gomez regeneration scene that we'll see on Saturday.

So far, for me: Delgado > Beevers (audio) > Gomez > Macqueen > Jacobi > Ainley > Beevers (TV) > Roberts > Pratt > Simm

Obviously, that could change next week. And Macqueen could be higher, but I've only heard him in Dark Eyes 2 (haven't gotten to UNIT: Dominion yet).