Took me over 5 years to upgrade my last card so probably not.
The same would apply to a GTX 970 because it's so close to GTX 980.
However, if you wanted the best performance
over time, GTX 970 upgraded to something faster in 2-3 years would be far better than holding on to GTX 980 for 5 years - for the same overall cost. A 5 year upgrade cycle for the GPU just isn't optimal in terms of performance for the money.
honestly the difference was negligable
i went from a
MSI N460GTX CYCLONE 1GD5/OC GeForce GTX 460 (Fermi) 1GB 256-Bit GDDR5 PCI Express 2.0 x16 HDCP Ready SLI Support Video Card
to
Club3D royalQueen CGAX-R927X6 Radeon R9 270X 2GB 256-Bit GDDR5 PCI Express 3.0 x16 HDCP Ready CrossFireX Support Video Card.
Interesting that you found it negligible. R9 270X is twice as fast as GTX 460. Since GTX 980 is also twice as fast as R9 270X, perhaps you will find that difference negligible as well

. Certainly begs the question whether the difference between GTX 980 and GTX 970 is meaningful.
Perhaps your CPU was bottlenecking the 270X.
And if so I can always SLI and make this GPU secondary.
SLI is always with two of the same GPUs, so GTX 980 SLI; you couldn't pick some faster card to SLI with the 980 and make the 980 "secondary".