I currently have a 15" Intel Dual-Core 2.8Ghz Glossy screen, 4GB 320GB with Express Card. Previous top model before they switched to the SD card slot. Its about a year old, used very little, excellent condition with no dents or scratches. Battery shows 89% good health, 140 cycles. I'm wondering if it is worth upgrading to the new i7 15" MBP with the HD screen and non-replaceable battery. I would really like the additional screen space and longer battery life. Do you think I could still get somewhere around $1600 for it? Is there a blue book value listing somewhere for reference? Thanks!