As I previously noted, I probably won't be able to explore this release at my day job due to our immutable requirement to support multiple versions of tools. I've raised this issues many times over the past couple of years and it looks like Rob has now taken notice of the problem:
Also, it is important to note that Votive in WiX v3.5 does not install side by side with WiX v3.0. This is an unfortunate design issue that we hope is fixed for WiX v3.5 upgrades to WiX v3.6.
I'm really looking forward to v3.6 ( because of Burn ) and hope to see this improvement in v3.6 so that I can actually use it in my environment. Until then, I will be using v3.5 in my own personal environment and I suggest that anyone who can move forward do so.