Claude 4 Sonnet feels off

Anthropic recently released Claude 4 Sonnet and Claude 4 Opus, and I’ve been using them at work for the last two days. 4 Opus seems okay, but 4 Sonnet feels “off” – less sharp than 3.7 Sonnet. My assessment is almost entirely vibes-based, just from chatting with the models and using Claude Code a bit.