I don't have any personal experience but have thought about putting a few of my Wheeler Dealer cars on BAT. However, the peanut gallery questions and the length of time it takes from getting accepted to auction finish have made me resist. But those were the days when cars depreciated and the 2 mo timeframe from start to finish could have an impact on price. I have a friend who sold his Beck 550 Spyder on BAT and he had a good experience.
Here's an article from Hagerty that cover's the author's experience. It seems pretty typical.
https://www.hagerty.com/media/buying-and-selling/is-bring-a-trailer-a-good-place-to-sell-your-car-absolutely-but-pack-your-patience/
Whenever I list a WD car on my usual websites, I always get a call from P-car Market. Early in their life I wasn't sure if they had the eyeballs & bidders but I think has changed now to where they're viable. My big reservation with them now is if the car doesn't sell, it goes into the Deal Tank for 3 wks. That's 3 wks you can't advertise it elsewhere.