I don't see how having regular auctions to determine what the land is actually worth is compatible with true land ownership. You auction the land to determine the tax, someone pays more than the current lessor, then that highest bidder gets to lease the land from the government and kick out the old lessor. Where does ownership of land and ability to sell it and profit from improvements come into play?

Unless you are in the Georgism-lite camp that says no auctions, just let government appraisers put value on the land as they do today and base the property tax on that exclusively instead of the current combined property tax. In this case you still have property ownership/buying/selling, which is far superior. I think the pros could outweigh the cons in limited situations, specifically downtown metro areas. But you have to accept a lot of bad pricing in this scenario, because these are the same assessors who allow all of those single story parking lots to profitably exist in downtown metros throughout the country.