Steam Index is great if you don't care about cords / needing a PC. Easy to do VRchat, IRacing, or even blade & sorcery game sessions for 3-4+ hours without any eye strain, headaches, motion sickness, or discomfort from the headset.
It also fits over / around glasses
Biggest reason not to IMO is of the rumors around an "index2".
I'll third this - Valve is really unobtrusive about the steam related features of the index. It does have some requirements with steam for setup but if you want to run a local binary and mess around with dev tools it's extremely easy to do. It's also extremely well sealed and designed - I tend to sweat a lot and a few times I've been beat sabering for quite a while without any long term damage to the headset.
> Biggest reason not to IMO is of the rumors around an "index2".
Another big reason not to buy a Steam Index is "not available in your country". The only VR headsets I've seen in stores here are the Quest 2/3 and the PSVR2; and the Steam store page for the Valve Index (and the Steam Deck) says "not available in your country".
It also fits over / around glasses
Biggest reason not to IMO is of the rumors around an "index2".