Similar to ZEN, BitcoinZ is based on ZCL as it is already mentioned in first post. ZCL is not maintained by owners. Latest zcash changes are not merged to ZCL for a long time. It looks like abandoned / centralized by devs chain.
Also ZEN and BitcoinZ is not competition. ZEN has dev tax which is managed by its team. In BitcoinZ there is no tax, no main / core dev team and community organized donations from pools.

BitcoinZ has different philosophy - it is continuation of bitcoin. No one can decide to change anything. BitcoinZ is fully decentralized, dev resistant coin.

BitcoinZ is based on Zcash and has latest zcash changes merged to it's core client. This coin has decentralized dev team. All changes from zcash will be automatically merged to BitcoinZ - no big deal and it is no huge effort to merge changes. That's why we don't need any dev fees.

All donations are managed by volunteers not connected to creators. bitcoinz-pod team doesn't collect any donations.
We have very stable zcash core which doesn't require any new features.
All we need is more adoption, recognition, new fancy wallets, integrations which we hope will be achieved by community donation fund managed by volunteers / community voting.

We believe in decentralization!