I do a lot of things with this PC.
Gaming obviously, but mostly on single screen. I sold my 2nd 560 ti by the time I got the three monitors. I've been playing surround gaming with single 560 ti using hacks and 3rd party software. Most dx9 games work with a little tweaking. I'm looking forward to upgrade to dual gtx770 gigabyte 4gb ones, but still wondering if it would fit with the hdd cage not removed.
I built this pc with future proofing in mind - how the whole rig would last for 2 rounds of graphic cards. The 1st gpu I sold to a friend, while the 2nd gpu I will sell to my brother as promised, as he owns the same exact rig with the same gpu but he not much of a heavy gamer, only on 1080p.
I play a lot with after effects and premiere, so having a geforce card does helps in premiere. Looking forward for more ram if prices go back down, it helps with the rendering. OC the cpu to 4.5ghz does help with sli gaming and rendering videos. Other than videos, I play a lot with sketchup, autocad, photoshop, illustrator, and some other similar software.
I do recording music as well. For I still can't find enough reason yet to get dedicated audio cards for my electric guitar, which I just plug in to the mobo line in. I do ASIO recordings and music compositions. About audio, being someone who mix sounds and music with quality sound in mind, I think even with the cheap z506 speakers and on board audio, the sound is good enough to enjoy movies and music so no need for audio cards.
For now, this pc is good enough for all these thing I do. But upgrading to dual gtx770s is a must for surround gaming.