Just my experience with gpt5:

First 2 tasks I gave it on cursor were (1) solve a problem using the rolling hash technique, given a rolling hash solution I already had for a similar problem as reference, and (2) translate the rolling hash code across languages.

It felt way worse than Claude 4 (or 3.5 for that matter).

I gave a few follow ups to try to help it, then gave up and restarted the task with Claude.

I have no intention of trying gpt5 again.