I would play 6 deck, HA .54, 80% pen, but I play games that many players would not consider.
I wouldn't travel out of my way to play it, but if there were other games nearby I would include it in my rotation and take a look each trip.
Did you post the rules somewhere that make up that .54 house advantage? I ask because if they include surrender, I would consider the actual HA to be lower as surrender is really worth significantly more to a counter. Especially one using a large spread like 20-1.