Ok, so I used the G20 this morning. I filled the reservoir and the bowl with hot tap water, as hot as it gets, which isn't the hottest. Showered, then started to prep the cream. I used Santa Maria Novella Creme da Barba. I poured the water out of the bowl, put a dollop of cream (about the size of 3 dimes), a few drops of hot water, and started mixing, adding more drops of water as needed. it made a good lather really easily (much easier than mixing it on my cupped palm). When I put the lathered brush to my face, it still felt quite warm -- and that's just with tap water. Water from a kettle should keep it even hotter. This thing works exactly the way it's supposed to. Get one soon.
Cheers,
Jack