How does the i5-3570K compared to later i5 models? Have they got any better or still the same? If you own i5-3570K, should you be worried about upgrading it?
If you have one don't bother upgrading it.
If you're choosing CPUs, choose whichever i5 CPU + mobo combo leaves you enough money to advance 1 tier up on your GPU. If you can't, go with the better CPU unless or save cash. You can also apply this thinking to just gaming CPUs in general (meaning including AMD from the FX-6300 and onward))
Going for 4690k also means upgrading my mobo.
Not worth it unless you need the newer z97 board features. The cpu aline is just not worth spending the money on. Wait for the next series.
the 4690k would be a better overclocker and it will run cooler... but if I have it I would just wait for skylake....
skylake! I'm just hearing about it from you.