i nmight buy a mz-nh600 questions: 1. can i use rechargeabel aa batteries in it? 2. can you skip albums and artist at a time? i dont want to keep pressing forward until my thumb hurts..lol 3. how loud does it go, the (uk version) ,with the ordinary sony headphones supplied with it? 4. what are the main things the newer ones have that this one doesnt? thaks, pease reply soon