> I believe the science is pretty clear that in principle these beat gas phase change systems.

Do you know by how much?

Gas phase change systems in practice are up to about 60% efficiency (relative to an idealized carnot cycle), magnetocaloric systems in labs have been something like 70%, and elastocaloric 80%.

Edit: And just for reference peltier devices are usually 10-15% efficiency on this scale. So I suppose this new one is somewhere in the 20-30% range.