Having spent considerable time in Sony 7506's and AKG 240's (newer, but not the newest, louder ones) this is what I've found:
- I prefer the sound of the AKG 240's - they sound more real-world, i.e. like speakers. They have a gentle high-end response that's clear but not harsh.
- The Sony's have a flatter, if not inflated high-end response that's great for really examining what you're listening to. In the end I think they're harsh, but a useful tool. They're loud too.
Example: I play a regular gig in headphones that has electronic drums - Roland TD-6, I think. They sound truly awful in the Sony headphones, and the cymbals hurt my ears so much that I have to keep the drums low in the mix. With the AKG's, the drums sound far more natural and balanced - I can get the kick up nicely without the cymbals splitting my ears. While most listeners would probably experience these 'drums' in an environment similar to the AKG sound, The Sony's are good to get a clearer idea of what they really sound like, or rather what's really going into the mix (whether you hear it prominently or not).
Each is about $100.