Upgraded from a 6870 to a 970 Superclocked and it's a noticeable step up. I'm running everything more or less full spec. I have the EVGA with ACX cooler setup. It was around 400$ in Canada but it's cheaper in the states.
I am an AMD GPU user currently (One HD 7950 w/ Boost in each of my Rigs), but i would also recommend the NVidia 970.
With GPU's, the market changes constantly because of price changes and new generations of cards. Both brands have great cards, so IMO it comes down to the best bang for your buck. When i bought my card, the 7950 w/ Boost for around $270-$280 was probably the best bang for your buck, but with the current market i think the NVidia 970 is the best bang for your buck.
I just looked and the prices have gone up some and there doesn't seem to be any sales or rebate offers going on right now, but a few weeks ago they were going for around $280-$290 and i believe they were offering a free game or two with most of them.
Now, i know that much money is at the very end of your price range but it's definitely worth it for the price and personally the $250-$300 range has always been the best or one of the best for getting the most out of your money.
The 970 will give you plenty of performance, so you won't have to worry about replacing it for atleast a few years IMO.
There is another great option too, especially if you would like to save some money but still have good performance. I looked on eBay a few weeks ago and i saw a few people selling brand new in box Radeon 7950's w/ Boost for $125. Which is a bargain IMO.
The 7950 is what i use in each of my rigs, and although it's a a generation or two old, it is still a powerful card and for $125, i don't think you are going to beat it. So i would check atleast check to see if anyone still has them for sale at that price on eBay.
I wish mine looked liked that, mine always looks like a rats nest.
Mine were all like that until i built my newest rig a few years ago. I bought an NZXT Switch 810 Case and since it had plenty of room for wire management i figured i wouldn't half ass it this time and routed all the cables so that there are as few cables showing as possible and so they are organized.
I will say though, that cable management can be very time consuming. Once you start, it's hard not to get all OCD and spend hours just making everything look neat.
I actually spent more time just on the cable management than i did putting everything else together when i built it lol.
You do get some bonuses out of your machine from doing it though too. You get much better airflow (obviously), it makes it a lot easier to work on everything or install a new part and you can much more clearly see what you are looking at and it also just plain makes your machine look better.
I think it was worth it, even if it was a little bit of a pain and time consuming.