VR is great for Sim-racing use once you get past the reduced image-quality and focus on the driving and racing itself. The overall immersion is really strong and the more feedback devices one has, the more convincing it becomes. Most of the time, I play titles with VR support but, there are times where I use triples to play some titles that don't have it. If it were a matter of only having a single monitor, I'd definitely always use VR for Racing / Flight-sims.
If there are significant gains in VR-HMD tech happening, developers are keeping them mostly under wraps but, there are some signs that good things are coming in the next year or two although, I suspect they may be more costly than we'd like given the small market that exists.
I don't think VR is going away - as some like to suggest, it's just going to be a lot slower growth and adoption rate than the industry forecasts suggested. Sim-racing is a niche market but, the adoption rate for VR should be relatively high compared with most other genres of PC-gaming because it works so well and is so much more immersive and enjoyable in VR imo.
I agree that "try before you buy" is a good practice but, there are some good deals on used HMD's if one doesn't have access to test one. If one suspects the chances of suffering VR-sickness are high for them, it's worth noting that some with very bad initial reactions have overcome them with some determination and patience but, it all depends on the individual. Slow and gradual is the key because when overdone, the consequences can be difficult to get over.
When combined with FFB, tactile and motion cues, the immersion with VR is stunning. It really is amazing to me that we have this tech to enjoy today in our own homes and I'm glad that I'm able to utilize it to enhance my Sim-racing.