Well, gpt3.5-turbo fails the turing test due to it's censorship and legal liability butt covering openai bolted on, so almost anything else is better. Now, compared to openai's gpt3 davinci (text-davinci-003) ... llama is much worse.
ChatGPT is GPT-3.5 Turbo.
3.5 Turbo is the ChatGPT model: it's cheaper (1/10th the price), faster and has a bunch of extra RLHF training to make it work well as a safe and usable chatbot.
https://openai.com/blog/introducing-chatgpt-and-whisper-apis introduced the turbo model.
MY MISTAKE: 002 and 003 are 3.5, but 001 looks to have pre-dated the InstructGPT work.