Does anyone have any experience of using this gear?

https://www.youtube.com/watch?v=c-fNkjTZ1g0

The vid says that the lighter weight - 75g lightweight material- "does need a bit of looking after to get the best performance from it" (is that code for delicate, breaks easily?).

Does it work as promoted? I quite fancy the tights for wild camping, fast-packing, and maybe the sleeping bag liner. But if it's a gimmick I'll save me pennies