Do you think it's worth spending that extra $300 , To get the GTX 590? To me it doesn't seem worth the extra money for the extra FPS you get. I only have $1300-$1400 , to spend on my new Gaming PC! It takes up almost half of my budget.
What resolution are you gaming at, what are the rest of your system specs (including detailed specs on your PSU) and what games are you looking to play?
In general, no, neither the GTX 580 or GTX 590 are worth what you need to invest into them.
You can get better performance, thermals and acoustics for quite a bit less with a pair of GTX 570s or 6850s.
Your build looks good, although you could potently save a bit of cash on the motherboard.
My recommendation for the GPU however would be a pair of 6950 2GB cards.
At stock they will give you similar performance to a GTX 590 and should cost about the same as your currentlz budgeted GTX 580.
The real fun would start if you decided to perform a BIOS mod as most 6950 2GB cards can have the disabled shaders enabled (effectively becoming a 6970).
That, with or without a healthy overclock, would give you a healthy performance boost over the GTX 590 at a much lower cost.
Any way you build it, be it a GTX 580 or pair of 6950s, you will still have a monster gaming rig
Well, anyways and again, your build looks good.
You could potentially save a bit by getting a less expensive Z68 motherboard, however.
That would also allow you to use your CPUs Quick Sync functionality.
As far as the GPU goes, I believe you would be much better off with a pair of 6950 2GB cards.
At stock, a pair of 6950s will effectively match the GTX 590 performance wise but should only cost about as much as your current GTX 580.
Additionally, most 6950 2GB cards can be BIOS modded into a 6970 quite easialy for an additional performance boost.
Any way you do it, it looks like you are going to have a killer gaming machine
I'd recommend a single 6970 (or 6990 if you got the dough)
so that the PC will be more upgradable.
but if you are not planning on upgrading it, then getting 6950 CF or 6970 CF is the way to go. of course this is from an apparently "AMD Fanboy"'s point of view, no offence to the NVidias, but I just don't like them as much. also, ponys are not gay; they are awesome.