I recently bought a pair of PK3's from a store, and have been really, really impressed with them. However, I did find the earbuds to be a little to mid heavy. Should I move on to the 580's or will the difference be not worth the cost? (I live in Thailand, and thus I buy from a specialty store that has to import them, cost me nearly 40 bucks for the pk3, 580 is around the same). Thoughts? My options are this: 1. Buy the 580's gift the PK3's to my mother or something. 2. Use the PK3's until I get enough money to buy the 980's or better. I read that the 580's were just lesser versions of the PK1. Is this true?