I would definitely prefer PE to be tied to N over it to be left floating. In the end PE and N connect to the same earth anyway. And, there are some earthing systems that actually combine PE and N, e.g. the TN-C system.
There is nothing to "prefer". If PE is "left floating" in a socket, is not just against code, it's a serious criminal offense; whoever did the installation should be investigated by the police. And, in all systems, PE
is connected to N, the only question between the systems is exactly
where. In old installations, it's well possible connecting PE and N together at the socket was completely legal, and normal during the time. Leaving PE unconnected never was legal. Because connecting N and PE together must be done with extreme care (risk of misidentification of N), it is understandable how connecting them together at socket has later become illegal, to minimize the number of places where this fatal wiring mistake can happen.
It's worth understanding though that
where and
how PE & N are connected is important for safety, so one must always treat N as live, and only PE as PE, and never assume otherwise.