You may find Claude giving better results. You can ask her to write code with "please apply technical guidance from Stephen Toub w.r.t. performance to the code you come up with" and it helps to improve the quality since Stephen Toub is someone she knows about. Or maybe some other core contributors and article authors that have more likelihood to be present in the dataset.
I'm going through each day and asking ChatGPT to speed it up, it doesn't always work, but that is the way of the Gippity.
The payoff is these heavy iterating operational scripts I run for work will end up running faster :)
Learning when to lean on some of the .NET primitives really helps speed up PS as it likes to wrap things with unnecessary features.