Well I feel kind of "happy", though that's not quite the right word, with the fact that the ATM50s are cited by many as pretty accurate, transparent cans, yet seemed to me to be boomier than my DT770s.
So, if I were to buy them and late-night mix on them, I wouldn't be doing anything different to plenty of other people on this forum, on a pair of cans that I consider coloured that other people don't. There are worse things - I mean, if all our ears were that suggestible to different cans/speaker systems, we'd all be totally screwed by all the noises we hear every day
I didn't buy them though. You'll all be pleased to hear I want to try out a pair of Sennheiser 600s first, just to see what all the fuss is about. (There's a scheme in the UK called 'Take It Away', which gives you 0% interest in certain music stores, making sinking £200 on a pair of cans less painful.)
Also, I had a bit of a mixing breakthrough yesterday, simply by compressing my vocals and acoustic guitar differently, and more aggressively, using much lower thresholds paired with lower ratios. I'd previously only ever used high thresholds and high ratios, essentially using compressors as not much more than limiters. Suddenly the tone of everything sounded a lot more even and controlled, a lot more "pro" and even when I cut or boosted at the extremes, they sounded like mix decisions rather than mistakes. The rough mixes I did yesterday still need a lot more work, but they were light years ahead of anything I've done before: they compare well with pro recordings on my Adam A5, my hi-fi and iPod.