The full 32 bits of your IPv4 address uniquely identify your connection, so no difference there. Someone looking at your IPv4 address doesn't know which device behind your NAT the connection comes from.
In Ipv6, you will have (as a minimum, it should be larger*) a /64 subnet to play in. Assuming you use privacy addressing, you therefore have 2^^64 addresses to play with, or 2^^32 times more addresses than the entire IPv4 address space. True, those top 64 bits* are as unique an identifier as a single IPv4 address - but you are no less worse off. But if done right, it will be impractical to try tracking multiple IPv6 addresses as a form of identification.
But this is moot anyway. Hardly anyone tracks you by IP address - just look at how well honed the likes of Facebook have got their tracking.
* Your ISP will get a minimum of a /32 allocation, and recommendations are to delegate /48 (or as a minimum, /56) blocks to customers.
Biting the hand that feeds IT
