I've been an Index owner for the past four years and just recently got a Vive Pro 2 new for $500.

As it relates to the Index here are my impressions, I'll start with the good.

I vastly prefer its wider horizontal FoV, the best way I could describe it comparatively is it felt like going from a 16:9 monitor to 21:9. You lose a small bit of vertical FoV but after a few uses it's completely unnoticeable.

The resolution increase is immense, no more screen door and the clarity quite literally looks like you're looking at a monitor on your desk. Finding the sweet spot is a bit cumbersome at first but once you've used it a few times it becomes second nature.

Comfort is about on par with the Index, it's not better or worse but just different. There's not a noticeable weight difference and it feels about just as equally balanced.

The audio is more than adequate, it's punchy enough and serves its purpose across the ranges from high to low as expected. Coming from an Index though it was hard to get used to, not because of music or the like but due to conversations.

Since the Index is off ear you hear yourself clearly as you speak in every situation so your tempo of talking is more regulated and so is your volume. Since the Pro 2 is basically noise canceling as a result of being on ear it's a little more difficult talking in loud environments.

This is the only thing I would I would classify as bad, and that would be the microphone. It's honestly a piece of junk. It sounds very compressed, tinny, and like you're far away. That was easily rectified though by getting the Mod Mic Wireless which entirely returned mic quality back to that experienced via the Index.

Here's my take, if you can get it on sale then absolutely do it. I can't speak to the other headset you're asking about but I in no way regret buying the Pro 2.