Help deciding which Z87 Motherboard to buy to pair with i7-4770k

I'd say #3 any other time, but #2 is much cheaper than both #1 and #2 and they are giving you free 8GB of RAM. In this case, #2 is the best value. Plus, you aren't planning on running your PC in the middle of a desert, right? So the benefits of #1's design is not really relevant. The only advantage of #3 is the BIOS flashback. Also, overclocking should be the same on all 3, the differences being the interface of the different BIOS's.

This article compares the same 3 boards you have chosen with the only difference being that they are 1155 Z77 boards. The "killer NIC" feature is simply a controller that takes the networking load away from the CPU. Having a 4770k, I highly doubt you will see a difference. What the article mentions is that if you want to decrease lag in multiplayer online games, simply turn off all your other programs and stop any downloads. The widi or wireless display feature can only perform as well as your router. I don't think that there is any difference in the LAN capabilities of these 3 motherboards. The only bottlenecks will come from your router.

From wikipedia's entry on Killer NIC:

"Early reactions to the Killer NIC centered on price, with its initial MSRP of $280.[7] This led to widespread skepticism and speculation that the product was merely attempting a money grab, hoping to cash in on the "bling" aspect of enthusiast computing.[8] However, using a F.E.A.R. benchmark IGN found that the Killer NIC increased framerate from 15.41 to 23.5 frame/s. While recognizing the potential for real performance gains, they also noted that the test systems were already struggling with the game, and that having a higher-end machine in the first place could offset the gains made by the Killer NIC. This supposition was supported by Anandtech's findings, which showed some real, but much less dramatic gains.[8] IGN declined to rate the card with a score, saying that more testing with other games would be needed. They remarked that the potential performance gain with the Killer NIC was probably higher than upgrading a $300 video card from one generation to the next. Anandtech noted that the people who would stand to gain the most benefit from the Killer NIC, the low-end users, would also be the ones least likely to pay $280 for a network card."

The tech does work and works best on low end systems. Since you plan on using the 4770k, this feature is almost completely irrelevant.

http://en.wikipedia.org/wiki/Killer_NIC