It depends... These are closed, the 599 are open. *Personally*, I like open headphones more (and the 599 are super comfy), but they don't block any external sound. If I'm using them close to a person on the phone, I can hear 100% the conversation. If you are going to use them in an office or "noisy" environment, the 280 make a lot more sense.
These or the 599 for the same price?
I've had these for 5 years, excellent sound and very well built. I'd buy again, but my old ones are still going strong!
In contrast I have a pair of the HD 380 for about 6 years and they're still going strong
Don't! They are fragile. I returned two of them.