Just to play devil’s advocate: you can’t compare Qwen to a (proprietary/closed source) hosted model and deduce that Qwen is overthinking, as Qwen gives you the full reasoning/thinking trace while all the proprietary models now give you only a summary “to prevent distillation”, making it hard to properly compare apples to apples here.
You can compare Qwen with thinking to Qwen with no thinking though. I find my results are better without thinking because of overthinking.
No, but you can compare it to the similarly-sized Gemma4 model and see the difference, it's not subtle
You can tell how long the cloud models spend thinking based on the delay.
The Qwen models have a habit of going into thought loops where they go in circles for a while.
People say Qwen overthinks because they analyzed the thinking traces, and Qwen finds the answer relatively quickly but then second guesses itself multiple times for another 20,000+ tokens. Regardless of what other models do, that's clearly overthinking.