When comparing ZCash vs IOTA, the Slant community recommends ZCash for most people. In the question“What are the best cryptocurrencies?” ZCash is ranked 8th while IOTA is ranked 10th. The most important reason people chose ZCash is:
ZCash is listed on Coinbase, arguably one of the easiest to use exchanges.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Traded on Coinbase
ZCash is listed on Coinbase, arguably one of the easiest to use exchanges.
Pro Anonymous
Decently Anonymous Cryptocurrency
Pro Anonymity - Coming Soon
Anonymous Transactions and messaging is on the roadmap!
Pro Fully Decentralized
Cons
Con Trusted Setup
In order to remain anonymous you must utilize a set of keys set by a group of individuals. If it got cracked or somehow leaked or if this group was corrupt your transactions might not be anonymous.
There is discussion to change this: https://www.starkware.co/
More Info: https://www.reddit.com/r/zec/comments/551wnw/what_is_the_trusted_setup_in_zcash_an_overview/
Con Centralized
IOTA is currently partially centralized due to its "coordinator" which is expected to be soon removed.
Con Unproven consensus mechanism
The new consensus mechanism is unproven against attack. Mana can be rented.
Con Not as Secure
It is arguably not as secure as other cryptocurrencies like NANO.