I switched some time after Anthropic bricked their models with adaptive thinking. It's a legit mystery to me how people are still using CC professionally.
Codex is far less frustrating and manages context better. It's also costing me about 1/3rd as much as Opus 4.7 on CC.
IME, based on an in-house bench it's still good to about 20% on the 1M for 4.6 and 4.7 with a code base >50k loc. The trick I used before switching providers was to have it write a handoff when it hit ~18% of context and reset.
There are also many people running 4.5 with specific parameters that claim to be having luck.
Codex is far less frustrating and manages context better. It's also costing me about 1/3rd as much as Opus 4.7 on CC.