Do not pass GO, do NOT collect $200 - Get the Z68.
(1) the added features to the Z68, quick sync, and the ability to later (or sooner depending on budget) to add a small SSD to cache a large HDD is worth more than the $30.
(2) The ability to run the monitor from the IGP (even though you will install a dedicated GPU. is worth the $30. Just built mine up, Used the IGP connection to verify that everything is working. Set-up on kitchen table (bare bones) to verify everything worked before installing in case. With Z68, you have a back-up video output should you need it - To me this is also worth the 30 bucks.
(3) Bottom line, At some point in the next 3 yrs, You will kick yourself in the Hindend if you bought the P67. I fully believe that manuf of mid->upperend MB will cut back on support for P67 (They say NOT, But.....)
For what's worth. Completed the Extreme4 build except for GPU, probably 6850, and SSD, (120 gig SSD Sata III) - should be here Wenseday. LOL - Messed up ordered it, thought it had not gone thru so re-order - ended up with two on the way, thought about calling them, what the heck can find use for the 2nd one. Any way, the build went fine, sofar no real cons, Still think I prefer Gigabyte's, but they only placed the video connector for the IGP on their LOW end models.
(1) Last three builds (not counting this one) have been gigabyte MB. Note one problem and the OC on two was very easy and rock solid. An E6400 @ 3.2 (DQ6) Currently my b/u the one I'm using now a P55-UD4P with a i5-750 OCed to 3.8 (Backed off to 3.2 as no real diff). My wife's system is an i3 on a microATX board - no OC - her desires. This falls more in the category of - staying with a reliable known working product.
(2) I prefered the layout of their BIOS, plus the daul bios was a good safety net. However with the Z68 I think they adopted a GUI interface.
(3) That "2 oz of Cu" was a good point - improves the ground plane and reduces signal to noise ratio.