Warm n Safe is excellent gear and they have the best Heat controller, (
Heat-troller) regardless of who's other gear you are using. I've been using their heat-trollers exclusively for over a decade.
Their jacket liners come in different versions. The wife has one of the Gen 3 women's heated jacket liners. It is thin and keeps her warm. What it doesn't do is give her a warm jacket off the bike. The WnS jackets are not insulated, so keep that in mind. The Gen 4 stuff is waterproof, but still no insulation, as I understand their web site. Great quality of gear too.
The wife's previous heated gear was Tourmaster. It worked ok, but had hot spots and the controller would die every couple of years. This was an older generation than now. Probably around 2009-13 stuff that she used. Perhaps they are better now?
I am still wearing a Gerbing jacket liner from 2004. It's insulated and I wear it as a jacket when off the bike when we are moto traveling. Bulkier than the WnS stuff. Back then it was a different company than today. Gerbing sold to someone else and
Gordon Gerbing has his own heated gear company now too. FWIW, First Gear heated gear is made by Warm n Safe. Some of the HD stuff was, but I'm not sure about currently.
Gordon Gerbing died this year. I have no idea what impact that may have or has had on his clothing company. His gear is insulated and essentially a nicely updated version of what I wear from 2004 with better heating elements. I'd consider that worth checking out.
Technology has progressed greatly from my circa 2004 jacket liner. Most companies are using carbon soft elements to heat and have flexible panels to keep the gear snug to your body. This helps warm you better, uses less power and provides a more uniform heat w/o hot spots.
There is a lot more out there, but this is what I know from personal use and have actually seen/handled or used. If I was looking now, I'd also look at the
Powerlet stuff.