Flexwatt is what everyone has used for many years, yes it has been adapted from home heating usage.
The new product from RB is well new, the quality and consistency remains to be seen as it will take a few years to fully determine. (multiple manufacturing runs and batch to batch consistency I suspect we are still in the same batch)
I am unsure when the first time it was available but I think it has been out a few months now? Perhaps Rich or Robin can correct me.
For my part I would like to know where it is made as it is clear rich and robin are not printing it them selves. I would also need to know if it is fully UL approved connectors and tape or just the tape. The Canadian laws for commercial application are quite clear.