"The ATX Z77 Fatal1ty Professional is similar to the X77 Extreme6 but seems to have some minor changes, including an extra PCIe x1 slot replacing the mini-PCIe slot, more PWM phases (better OC'ing), dual-ethernet ports and less display outputs (DisplayPort and HDMI only)."
Hope that helps you decide...
Since you didn't mention a graphics card, I'm guessing you're using the integrated Intel graphics on the 3770K, so you of course need a board with DVI/HDMI output. If you do have your own graphics card, another option is the Z77 Professional
yea i knew it deluxe had loads of features plus performance is also gr8 but not going for it because its not available in my country as of poor support by asus. so had to stick with asrock and was confused in choosing between fatal1ty and extreme6
your reply helped me decide to go for fatal1ty. thanks much