We have a wealth tax in parts of Switzerland. It works for normal people like me where you can value my house and bank accounts easily. But it starts to have problems when you're ultra-wealthy and you have to value my artwork - paintings, sculptures, jewelry...
Overall I think it's fine. I think where I live it's .75%. But there's a giant hotel where the fifa executives live and the owner keeps getting in trouble for importing art and undervaluing it.