The ollos seem interesting but they will suffer from the same issue that all spacial audio suffers from when used with headphones or IEM: they are using generic HRTF profiles. It could be perfect for some portion of the population and then absolutely horrible another. It all comes down to how far your own HRTF varies from the population from which they've measured the HRTFs.
I'm order to be able to localize sounds sources in a manner that is very close to real-world experience, you need to have a VERY closely matching HRTF, otherwise things will sound bizarre and uncanny. It's a bit like trying to wear the glasses of someone who has a totally different prescription, except there's FAR more variables that the head-related transfer function has to match.
I'm very tempted to buy a pair so I can compare them to my own headphone rig, since I have captured my own HRTF with incredible results. Being tied to WavesNX for the virtual room is a no-go for me though. I already own it and it's worthless for my ears. It offers EQ correction to match a target curve that is much more flat to most people ears, but I don't need that since I EQ all of my headphones already and have been for years. And, unfortunately, the two parameters that they let you customize aren't enough to provide strong localization.
Head circumference and ear distance will only have a noticeable effect below a certain frequency threshold. Those measurements will only affect the Interaural Delay you experience and therefore it has practically zero benefit to localization above 1.4khz. The lower the frequency, the more humans utilize ITD, but we don't use it at all when the frequency is above that threshold. The information that humans use to determine locality of a sound source above 1.4khz is simply the shape of your ears, mostly the pinna (outer-ear). That shape drastically changes the frequency response that we hear. So as long as generic HRTFs are being used, it's entirely luck of the draw whether or not their HRTF measurement(s) will make the experience better or worse.
Every generic HRTF I've ever tried has made things worse for me, and I've tried a LOT of them through HeSuVi. You can check that out here if you're interested:
https://sourceforge.net/projects/hesuvi
I'd be VERY interested in the products if it included virtual room modeling that didn't require being connected to a computer, but that's not the case yet.
