PIVX's PoS system allows for greater decentralization and equitable block reward distribution. PoS is also not vulnerable to 51% attacks. https://blockonomi.com/51-attack-calculator/
Question: privacy in PIVX is optional, right? Are private transactions more expensive than regular ones?
This mint and spend system can result in tx's that use multiple denominations and thus cost multiple of 0.01 PIV, but reverse is true, can get multiple anonymous tx's from a mint.
Question: privacy in PIVX is optional, right? Are private transactions more expensive than regular ones?
Yes, PIVX has privacy opt-in. Regular tx costs can range from free to the 0.0001 standard fee. SwiftX is 0.01 PIV for instant confirmation. Each zPIV denomination mint costs 0.01 PIV.