I've tried Copilot, Aider and Cursor and the best I've found is to just use the various chat interfaces. I sometimes throw hundreds of lines straight in there, and the models seem to understand the full context much better than any "LLM Editor" I've tried so far. Then different models are good for different things (obvious maybe). For example, O1 Pro is miles ahead any models when it comes to overall architecture, R1 is great for finding nasty bugs and Sonnet great for small and fast feature additions/modifications with strict requirements.

You will. Cursor is much further along on the journey of building an actually powerful AI coding system. Since they are smaller, they can afford to iterate more quickly and experiment with a much tighter feedback loop.

I have used Cursor and my own MCP codemcp. Cursor has a lot of nice QoL that you can't get from an MCP package; the TAB is really good for traditional coding. Haven't used copilot so I don't have a comparison there. Definitely use agent mode.

It doesn't matter. They're all thin layers on functionally equivalent models. Stick with whatever text editor you prefer.