The MDR F1 definitely shares some similarities to the MA900 in sound, but the latter is a bit of an improvement overall. The F1 is a tad more rolled off in the highs and a tad less detailed overall. I found the soundstage on the F1 to be a bit overly diffuse and holographic when used with Dolby Headphone.
The Q701 is a more detailed headphone and has sharper and more discrete imaging/positioning when used in Dolby Headphone. So yes, the Q701s are better for sound whoring.
If all you care about is sound whoring though, the Q701 is overkill, because it won't sound whore any better than an AD700(x) or HD5x8. It will mainly be more immersive.
Thank you for the info! I like my F1's, great comfort, but wanted to try something different as well. Had a pair of AD 700's already, but comfort/fit was issue for me. I'm gonna try out some Akg q701's and see how it goes.