Mastering Question : -10db rms enough for you?
I don't care. I push until it starts sounding bad. PERIOD. being -15 or -9.
I find some mixes start sounding bad at -15 some sound fine up to -9. It really depends on the mix.
I think it depends on the the music asks for.
Metal, well, clients generally want it loud.
Other stuff, well, depends. I tend to use automation for stuff that needs to be very dynamic yet really loud in parts (post rock/avant garde stuff).
For me the line is when it's starts sounding overcooked. I don't care how many RMS or peak it is, that's just numbers.