280's are the best closed headphones anywhere near their price. Although they are quite bulky, I also travel with them because they do a reasonable job isolating the noise on airplanes and are very comfortable. They sound good without an amp but better with a Grado or Musical Fidelity amp.
The HD25s aren't full-ear phones. The 280s will cover the ear completely, which is better for isolation and better for recording (if that's the intent). Otherwise, the 25 may sound better than the 280. Don't know.
I just bought a pair of these myself last night. So far, I'm stunned by the sound quality - I've never had good cans before, just cheapies. These things sound amazing!!
I'd been poking around at the reviews on epinions.com, and many people recommended doing a burn-in with these for best sound quality - I've had them plugged into my PC with different CDs on shuffle for 24 hours now, and the bass response has improved noticeably - I'm going to give them another 24, then stop - that seems to be the amount most folks have done. I could just be a doofus, too....who knows?
No you're not being a doofus (at least not here ), to be honest the burn-in does work. I didn't notice a difference in bass afterwards, but the treble, which started out just slightly too brittle, was tamed perfectly after a few days of constant play. Glad you like them - Sennheisers are great phones.
These headphones work great. The isolation makes it a lot easier to track guitar. I don't use them for anything other than recording, so I can't really comment on other uses. I will say they are very comfortable like others have mentioned.
I bought them for dual use as live engineering and recording cans, and I like them. I wanted circumaural closed-back phones, and they fit the bill. I was unaware of any burn-in proceedure, but they have become a lot more natural after extended use... maybe still a bit bass-heavy, but not annoyingly so. Not as natural as a good open-backed design, but you wouldn't be shopping them if you didn't want the isolation.