Locknuts on 07 July 2013
It's not nice being a beta tester. The best rule of thumb I've found is to let the software guide your decision to buy the hardware. Unless you're sure that the PS4 has something you will love at launch, I wouldn't pre order it or any other console. There are always issues that need to be sorted out with new hardware.
Personally, I plan on finishing my PS3 and Steam backlogs before I invest in a PS4. Oh and GTA5 too.
