The lack of transparency around model quality/usage limits on closed models makes me want to ditch them.

What I have learned is that any model from Anthropic/OpenAI is at it's absolute best right after release.

This isn’t really specific to LLMs, though, is it? Pretty much any modern SaaS product will silently siphon off some portion of requests off to stuff they’re A/B testing before release and you’ll not necessarily know about it.