So it looks like the property that the Swiss system sacrifices is receipt freeness. In short, there is nothing to protect voters against someone coercing them to reveal their vote.

In a first world country like Switzerland it's unlikely this coercion would take place with an AK47 at the ballot box. It is, however, conceivable that it could take place on the shop floor by either a boss or a trade union representative threatening to withhold work or pay.

I wouldn't be comfortable using a system like this for a state level election. The stakes are too high. That said, I do actually offer a product that sacrifices the same property and is designed to be used in elections for community organisations, companies, etc.

My digital election product: https://scrut.in/

More information on the concept of receipt freeness: http://www.lsv.fr/Publis/PAPERS/PDF/DKR-csfw06.pdf