I played with aider a few days ago. Pretty frustrating experience. It kept telling me to "add files" that are in the damn directory that I opened it in. "Add them yourself" was my response. Didn't work; it couldn't do it somehow. Probably once you dial that in, it starts working better. But I had a rough time with it creating commits with broken code, not picking up manual file changes, etc. It all felt a bit flaky and brittle. Half the problem seems to be simple cache coherence issues and me having to tell it things that it should be figuring out by itself.
The model quality seems less important than the plumbing to get the full context to the AI. And since large context windows are expensive, a lot of these tools are cutting corners all the time.
I think that's a short term problem. Not cutting those corners is valuable enough that a logical end state is tools that don't do that that cost a bit more. Just load the whole project. Yes it will make every question cost 2-3$ or something like that. That's expensive now but if it drops by 20x we won't care.
Basically large models that support huge context windows of millions/tens of millions of tokens cost something like the price of a small car and use a lot of energy. That's OK. Lots of people own small cars. Because they are kind of useful. AIs that have a complete, detailed context of all your code, requirements, intentions, etc. will be able to do a much better job that one that has to guess all of that from a few lines of text. That would be useful. And valuable to a lot of people.
Nvidia is rich because they have insane margins on their GPUs. They cost a fraction of what they sell them for. That means that price will crash over time. So, I'm optimistic that a lot of this stuff will improve rapidly.