Can anyone tell me what the specs are on the Superdrive that shipped with the first version of the Macbook pro? Read speeds, write speeds, etc. I believe it writes DVDs at 4x and no dual layers. Is it feasible to replace the Supedrive with a newer, faster model? Or are the newest ones not that much faster to justify the price? I need the ability to write to dual layer discs, but significantly faster read speeds would be great. I have been looking for a decent external drive but if I can get a good internal drive instead I'd rather do that, if it's worth the extra cost. Any tips are welcome - thanks!