As someone who has purchased multiple $1000+ headphones and has demoed several more, I'm of the opinion that purchasing more expensive gear doesn't typically equate to greater appreciation for one's musical selections. To me, the whole notion of pursuing "summit-fi" is largely a consumerist rat race. Attempting to compare the DT250-250 to, say, the HD800 will draw cries of "apples to oranges" largely due to price and partly because of form factor, but to me a headphone is a headphone regardless of these attributes -- the application remains the same. (personal listening devices, both) Without getting into specifics that may cause a rift, (PM me if elaboration is needed) based on my time with the HD800 I prefer the DT250-250.
Point being, don't discount the performance of your current gear based on what could be greener pastures. If you don't desire more of 'X' or less of 'Y' out of your setup, then just sit back and enjoy the music.
that's quite a controversial statement, if that's the right word, and quite an endorsement of the dt250! Nice to hear from someone who doesn't always feel the need for more, more, more. Imo, if you find a set up that draws you into the music and makes you forget the gear, then you're already there. I get to that point a good deal of the time. I think a lot of upgraditus comes from boredom with the music itself... so we need to find the next big shiny toy to keep us occupied. I have no need to upgrade other than out of curiosity as to what a good ortho could do. I like what a modded Fostex t20 was capable of and the Paradox modded T50 is supposedly much better. But that's curiosity, not need.