This aligns very closely with my experience.

When left to its own devices, GLM-4.7 frequently tries to build the world. It's also less capable at figuring out stumbling blocks on its own without spiralling.

For small, well-defined tasks, it's broadly comparable to Sonnet.

Given how incredibly cheap it is, it's useful even as a secondary model.

Anecdotal, but I've been locked to Sonnet for the past 6-8 months just because they always seem to introduce throttling bugs with Opus where it starts to devour tokens or falls over. Very interested once open models close the gap to about 6 months.