Just buy 'em all! (I need to get out at night, methinks). Checkout the LaserLock read speeds in the sticky pinned in the Experienced Forum.

The ASUS 48 is not much faster than the 40x. The 48x has slow disc recognition times. The 40x is a dream. The ASUS are quiet and don't require a plethora of FW upgrades (don't get me wrong, I love my Liteys). If you were thinking of buying a LTD-163 or SD-M1402 then with an ASUS, you don't need 'em; but, I guess that most ppl have a PC DVD player anyway.

ASUS/Liteon plus 163/1402 - can't go wrong