wd2p88288wrote a review of Burton Toaster Snowboard Boot Liner - Men's on April 4, 2018
Familiarity: I returned this product before using it
I have an older Burton SLX boot that came with liners that have built-in heaters. Unfortunately the connectors were made from the cheapest plastic and wiring on the planet, they subsequently cracked and broke off. I had hoped that the Toaster liners would have been a replacement, but they are too big and too puffy even though the footprint is the same as the old liners.
It was a struggle to get the liner into the SLX shell and when I put my foot into the boot, it was too tight because of the Toaster liner material is too thick. It was also a struggle to get the Toaster liner out of the SLX shell afterwards.
The Toaster liner with the Li battery is a great idea, but I think it has to be designed as part of a boot rather than an add-on or replacement.