In the transcripts I saw, it seemed like Sydney repeated itself a lot. It used the same sentence structure a lot. Stephen Wolfram wrote a good primer on LLMs, which was recently discussed here a lot:

https://writings.stephenwolfram.com/2023/02/what-is-chatgpt-...

To my eye, BingGPT's personality looked similar to the early "low-temperature" examples in that article. Like the model got stuck overfitting to a topic that acts like a local maxima of word probabilities.