I've been working as a programmer for almost 15 years and I work on fairly touchy (perf, reliability-wise) networked systems in a programming language with a good type system. I find Copilot to be very valuable even if I have to give it a little bump or edit what it produces sometimes.
I'm definitely not more junior, and I'm seeing massive productivity improvement from Copilot and GPT-4 - but I'm finding it takes a lot of expertise to get the best results, both in my ability as a programmer and in terms of knowing the best ways to use the AI tools.
Learning how to get the best results of them takes a great deal of experimentation.
This has been my experience as well. I actually avoid recommending Copilot to juniors because I think using it requires a deeper understanding of what you're trying to do than is required to just write the code by hand. When you have that understanding it can be a huge time saver, but it's not something you can just pick up and magically ask to solve your problems for you.
I’m curious what your workflow is like switching between copilot and gpt-4. I typically have an open window for each, though this can feel more cumbersome than necessary at times.
I actually use the ChatGPT UI more than copilot - I write code with it while I'm out walking the dog, by describing what I want, then copy and paste it into my text editor on my laptop when I get home.