It can't replace search, actually. It doesn't know everything a decent search engine can find, and might not even remember the specific php command line parameter you're looking for.

What it can do is reason some pretty tricky interdisciplinary answers. It's about as useful as having an intern that's finished literally every white collar college out there but has no idea what they're doing. It takes some prompting to get useful work out of it but it is possible and it is very effective when you get it right.

The $20 sub has saved me quite a bit of time, the main challenge is remembering to set it to GPT4 for every damn conversation, as the previous models are trash.