I am running Windows 10 with a GTX 970. In my attempts to get 3D Vision working with ESO, I've run into a few problem.

DX9 is required for the Helix mod. I found that DX9 on a GTX 970 both runs terrible and suffers from a major memory leak. At character selection, the game process spikes to 2GB and if you load into a major city it will immediately spike to 3.2GB. As you run around, it will increase to 3.6-3.7GB; resulting in a crash (32-bit program limitation). This is in regular 2D mode without 3D Vision. The time to crash can usually be measured in a few seconds or a couple minutes. It happens inevitably.

DX11 runs fine for me in 2D; no issues. For 3D compatibility mode, the game needs to run a true fullscreen mode. However, both "Borderless Window" and "Fullscreen" both run the game in a borderless window. Prefer exclusive mode is enabled in my ini file. I can confirm that full screen mode works in DX9 mode (albeit unplayable). Another downside of the lack of true fullscreen mode is that you lose the option for a mode that generally gives better performance.

If you have a GTX 970 and running Windows 10, you're stuck with running the game in D3D11 borderless window mode or you'll suffer from memory leaks. Its not optimal... and personally I hate it, but that all I've been able to come up with.

I hope I save someone some time with this.