There's a clear situation where the reality that this is effectively a 3.5GB card matters, despite the fact that people are getting the 1080p/1440p performance they thought they would: going SLI to game at 4K.
The GTX 970 has now been outed as a fairly poor choice for such setups, and almost no one could have known that based on the launch-day reviews, which reported that this was a 4GB card and benched it almost exclusively below 4K and in single-card setups. Yes, you could find 4K SLI reviews (e.g.,
http://www.techpowerup.com/reviews/NVIDIA/GeForce_GTX_970_SLI/20.html), but the truth is that most people aren't gaming at 4K yet, and we don't know how future games will perform at 4K. What we do know is that VRAM matters, and this card is lacking in that crucial area.
I don't care about the ROPs or cache, but this is a 4GB card like the 660 Ti was a 2GB card, i.e., it's literally true but effectively false. Did it or does it matter to most people? No. Did it need to be divulged like it was in the case of the 660 Ti (see
http://www.anandtech.com/show/6159/the-geforce-gtx-660-ti-review)?
Absolutely.
Note - I'm not voting in the poll as I don't own a 970, but I thing 970 owners should be concerned.