What's your monitor setup and resolution?
I will be getting a new Dell Ultrasharp U2413, 24 inch, 1920 x 1200, entry-level professional IPS monitor. It has 6ms overdrive, so it can decently game as well. I'm staring with a single monitor setup, with the possibility of a second monitor but I don't have a compelling reason to justify that at the moment. For connectivity, it has everything but VGA, so I'm set. It can even daisy chain a display port. It also has hardware 1:1 scaling so I can run natively at 1200, 1080, or any other resolution for frame rate if needed. Great for DOS games, too.
Realistically, choosing between similar cards on the same GPU core isn't going to offer up a night-and-day change in the long term. There's some logic to buying the best you can afford if it's a long term investment. But, the 970 does offer the lowest power draw and best price v performance ratio.
The 970 can handle max settings at 1080 for current games, so it's more than enough for 60Hz refresh rate. Of course, its performance will taper-off with future games, and the last 0.5GB VRAM debacle will definitely show up by then. The 980 is able to age a little better and has all 4GB of full speed VRAM. Gaming is only a tertiary role. The extra performance for encoding and rendering is what also interests me. I'm aware that it's not night and day, that's why I'm at odds trying to choose between them. I may have the budget, but justifying the purchase is a different story.
Personally, I try not to get too attached to my kit. In some circumstances I'd rather sell things on while they still hold some value, rather than use them until they become borderline obsolete. I recall picking up an Asus 660Ti in 2011 and ignoring the 670 because I knew that my base system had plenty of mileage in it, with the GPU being the one component that might show it's age first; I sold it last year for a little under half of what I paid for it.
The video card is always the weakest link. For me, I tend to stay with it until the market price becomes dirt cheap, then I continue to milk the base system until it becomes too slow, rather than spending on incremental upgrades. That's why I allow myself a large budget, because I have not upgraded in many years. Naturally, reason comes into play and tells me to keep it down and not squander it. Hardware within the last decade don't become obsolete as quickly as the years before that, so the base components might last me quite a while before a complete overhaul is needed.
I appreciate your comments. Your perspective makes me seriously think about my upgrade cycle.