Basically I am about to build a pc for my wife and upgrade my own pc, so I will already be purchasing a 4770k and a new motherboard. The question is whether or not I purchase a high end board and use it in my own rig which I will be overclocking, or whether I stick with my 3770k and put the new processor in hers.
She only does light gaming, so either processor will be great for her in the pc I am building, I am however looking to push multiple monitors at 1440p and above. The Asrock z77 is a pretty solid board, but I don't know if I want to hang SLI 780 ti cards from a budget motherboard.
I am well aware that the 4770k and 3770k are very very similar in performance, with them flip flopping depending on overclocks and luck of the draw in the comparisons I have read. So it comes down to whether or not the performance gain from a high end z87 motherboard warrants me dropping the new processor in my own build.
Personally, I'd upgrade your machine with the socket 1150 CPU and new motherboard. There are some awesome (and a larger selection of) Z87 gaming motherboards out there and the next gen CPUs (Braodwell) will be socket 1150 from everything I've read and heard. Since your original 3770K is socket 1155, it's a pretty dead-end upgrade path, with fewer options (in terms of CPU/mobo upgrades) whereas socket 1150 will probably see some new motherboards with the arrival of Broadwell later this year.
I doubt the 1150 socket will see enough of an advancement to warrant dropping another processor over the 4770k in this build before intel swaps sockets again. Unless broadwell makes a bigger performance jump than I have seen from intel in a while. I'm really just wondering how big the performance gap will be from what I have now to a top tier motherboard with the 4770k. I am just not sure how much more actual gaming performance I would see from an Asus Maximus board.
The top-tier motherboards usually won't provide a significant performance boost over your current AsRock motherboard. However, what they will probably provide is a higher/more stable overclock (as long as your aftermarket cooler is sufficient) due to better/higher quality pcb circuitry (trace thickness and VRM) and possible beneficial features that your current motherboard does not offer. So really, it will be your call since in most cases, overclocking typically only provides a 5-10 % performance increase.
Another thing I will mention is that if you give your wife your existing CPU/mobo, the OS license will not care what other parts are used and still work with the new system. However, if you decide to keep your CPU and upgrade your mobo, in all probablilty, you will need to purchase a new OS for it (plus one for your wife's build).
I don't plan on swapping the motherboard with my 3770k in any scenario. I'm not willing to risk it screwing my windows install and then trying to convince microsoft support to let me reinstall my OEM copy again. I actually have another windows 7 license so the only way I'll end up paying for another operating system is if I decide to go with Windows 7 Pro just for the 32GB of RAM.
This really wouldn't even be a debate at all if it wasn't so cheap to make the swap right now. The Biostar board I was going to buy for her is only about 60 dollars less than the Asus Maximus I was looking at buying if I used it for myself. It really seems like there is no clear answer but I do appreciate the input from everyone.