What kind of levels are you monitoring with throughout the record making process, and does working with loud music usually equal a loud control room for you? Have there been times when an artist wanted it LOUD, leading to some records being made on far fields more than nears?
First thing about mixing: I try to keep the client out of the room if possible until the mix is 98% complete. I want the client make a judgement on the entire landscape instead of having them listen to each individual track as it is placed into the picture.
While sculpting the overall mix structure, I start with the monitors at moderately loud levels. I pop the mix up to the large main monitors for a little while as I shape the lowest frequencies, then bring the mix down to the near-field "one click" setting on the Neve to make sure the vocal levels sit nicely in the track. Finally I like to do a headphone listen to make sure there are no hidden problems with edits, panning or digital artifacts.
I find that louder monitoring will mask unwelcome distortion problems and seduce you into thinking the vocals and cymbals are perfect, when at lower levels you will hear them screaming loud in the mix. Also- louder monitoring will fatigue your ears much sooner, making your next mix more difficult. Lower level "one click" monitoring is essential to find the vocal placement for me. Even checking the mix from an adjoining room is a good test to see if your mix is as tasty as it can be!
Of course when the client is finally allowed in the room, I'll crank up the levels for the first listen. Nothing like a little volume to impress!
I use NHT Pro M100 monitors for the majority of the time while mixing, with Genelec 1035 mains and Yamaha NS10s for near-field detail work. I live in my Beyer-Dynamic DT770 headphones. Love the plushy earfoams. Mmmmm.
By NHT Pro M100 do you mean the (now discontinued) MOO's? I looked up M100 and can't find any such thing. Closest I saw was the M-00, which seemed both remarkably inexpensive, and widely used by pros. What's the attraction?