I might be alone but I feel that if a track takes too long to master I lose the ability to bring my most important asset - objectivity. If I have to spend as long turning knobs as the mix guy did I can safely say we're in deep water...and sinking.
I aspire to having a room, gear and workflow where I can instantly hear where a song needs to go, intuitively take it there with minimum "thinking" and spend my energy concentrating on preserving or enhancing the feel of the music.
Sometimes you get a track with a weird problem, say a very particular type of ess problem that requires MS or whatever. In these instances I try to do the necessary broad strokes before I get lost in the jungle of minutiae.
I do a lot of unattended work and I find that if I'm struggling with a track for whatever reason that I'd rather spend 30 mins in two separate goes that slave over a track for too long.
Cheers,
Ruairi