In my experience all those factors matter significantly less with the 9200 than with most other headphones as it's quite easy to drive and absolutely not picky as long as you don't pair it with something overly bright.SilverEars,
there are so many factors at play here, like the device (source), balanced or single ended cable, has it been burned in (I found that my 9200 improved significantly after about 250 hours), the recording which I personally find a major factor, and so on. Also pairing (match-up) can make or break your experience.
I bought an upgrade cable (Fiio Lc-Re) for my Beyerdynamic Xelento inears, and they opened up the soundstage considerably.
I'd be interested to know about the rig you are using.
I do agree though that open backed would sound airier and more open, but as far as closed backed headphones go I haven't heard anything better in this price range. The Focal Stellia is like double the price and still I find the 9200 a lot more engaging.
And i honestly doubt that your D9200 improved significantly after 250 hours of burn in. How do you guys even know how many hours you got? Do you sit there with a stopwatch?
I do agree though that it's one of the best closed backs out there especially if you want something uncomplicated driven from a dap.