I just compared the KDL52WL135 (2999 at Costco) and the KDL52XBR5 (4300 @ best buy). What are the differences that may a 1000-1300 difference? I pulled the specs and noted the following: the frame of the XBR is a little sleeker/fancier, WL has a bravia engine ex video processor, XBR has bravia engine with Pro HD video processor, XBR has front surrounds/digital amp (I don't need this anyway), XBR dynamic contrast ratio is 18K vs. 16K for WL. I'm I missing something?