I agree with you, it's personally hard to tell.

For me I've noticed it getting nothing but better over the past couple months, but I've been working on my workflows and tooling.

For example, I used to use plan mode and would put everything in a single file and then ask it to implement it in a new session.

Switching to the 'superpowers' plugin with its own skills to brainstorm and write plans and execute plans with batches and tasks seems to have made a big improvement and help catch things I wouldn't have before. There's a "get shit done" plugin that's similar that I want to explore as well.

The code output always looks good to me for the most part though and I've never thought that it's getting dumber anything, so I feel like a lot of the improvements I see are because of a skill issue on my part trying to use everything. Obviously it doesn't help there's a new way to do things every two weeks though.