Nxt has such features as

# Instant transactions ("0-confirmation transactions")
# Anonymity of IP address send transactions & mining blocks (with Tor or the cloud client)
# P2P exchange BTC (with colored coins)
# Faster difficulty changes (adjusted each block)
# Name doesn't contain "coin", "cash", "kash", "money", "dollar",  nor "bit" (at least now, Nxt is a codename)

VISA scale volume can be achieved with 32 Mbps connection.

I can not give an answer regarding Zerocoin/CoinJoin now, I am not very familiar with these concepts.