PIVX community is almost finish readying the new wallet implementation of the new anonymization protocol, zerocoin protocol with the release candidate 3.
https://forum.pivx.org/t/pivx-core-wallet-3-0-4-rc3-release-10-25-2017/Have you tried it? What do you think? I did try better...
It works great, in a few second it's possible to transfer any amount of PIVX to the "accumulator", and then they are transformed into ZPIV, it means that you have a proof of what you send in the pool of the accumulator written on your wallet.dat (upgrade often), and when you wish to withdraw what you own and transform them back to PIVX it goes almost instantly.
so yes zpiv is a proof of ownership of your coin who are pooled in the accumulator, and which can be converted back to the public chain.
One of the limitation is that there is only certain domination that can be anonymized like (1, 5 10 50 100 500 1000 5000), meaning that if you convert 10.324 pivx to zpiv (send in the accumulator) you only get 10zpiv (private) and the change is sent back to pivx (public). However it's so fast and easy to use that I think it's the best solution I have seen.
So PIVX has a robust old chain with a great and honest dispersion of coin ownership due to it's fair initial mining phase, and now having successfully integrated the masternode (coinjoin idea) it has moved to a fully decentralized anonymization system.
Simply the best PoS coin?