the most important improvement that Valve/HTC should make on the headset

Phones already have higher-resolution displays than the Vive, with more and non-PenTile pixels. Lighter weight. Wireless. World-scale tracking. Better AR UX.

It looks like external GPUs with thunderbolt usb may become mainstream. Imagine a phone optionally wired to an eGPU and cloud cpus.

So perhaps Valve is squeezed between an arcade and professional high-end, and a phone low-end? While being afraid to fragment the consumer VR gaming hardware market, by moving too fast, or being too expensive. So Valve might focus on price, and make only incremental improvements, in an effort to expand VR gaming market participation, but a market with phone-like specs might gravitate away towards phones?

For myself, my interest is in doing software development inside of VR, rather than games. If you can't read text, there's not point. So my priority is angular resolution, followed by angular resolution, and angular resolution. I'm willing to trade FoV, computes, frame rate (down to 30fps), dimness, blur, and other artifacts, weight and wires, all for resolution. And expense. If "retina"-ish HMD Varjo works on linux, and costs $3k USD, no problem.

So I would like much higher resolution, but I don't know how hard Valve/HTC should push that.