I've had roughly equal inputs from both sides.
My current setup is basically my first ever PC build. At that time, there was a lot of talk of people waiting for Sandy Bridge (Dec2010/Jan2011). I didn't wait, as I had time off, and I didn't have a gaming PC at all at the time. Now, it doesn't matter so much. I do have a very capable PC.
The main issue is, if I put money aside to build better, later, I might spend it before I build. My biggest concerns are that the 700 series of graphics cards has been out longer than many recent generations. Also, games recently have been really upping the textures and VRAM use, so having 3GB could be a concern (although in that case, I suppose I should go for a 6GB 780). I dislike AMD's drivers and software.
According to the CPU and GPU charts on Tom's hardware, I'm fine with my current CPU, but could see real benefit from a new GPU. Of course, being a member of this forum, many of my preferred games are CPU bound (even if I like the less cerebral stuff, too)