I'm now much more in favor of a Georgist-style land value tax, where wealth taxes on natural monopolies like land are the only form of taxation. This biases the society toward action (if you don't make enough money to afford the opportunity cost of your continued ownership of the land, you lose it) and aligns incentives much more between renters, landlords, entrepreneurs, and municipal governments.
I do think there needs to be standardized, publicized assessment methods that are independent of politics and local government employees. Otherwise there's too much of an incentive for governments to fudge the assessments to increase the tax revenues they can generate. Really, this is a task for a computer: run a regression on comparable sales and take human judgment out of it.