Hey I was eventually going to get around to asking The Big One. Might as well be now.
I hope this doesn't violate any Dharma Wheel accepted-discussion laws? If it does, I couldn't find such a rule in the posting guidelines.
I'm hoping this will be a friendly exploration of alternative answers (or non-answers) to the question of whether there is/isn't a Buddhist ultimate ground, not an arena for "My (non-)ground's better than yours!"
No one really knows anything. (I think.)