There was only ever a 6B GPT-J, you must be thinking of GPT-neo's for smaller sizes. GPT-J was the best of its kind for a long while but even just the 7b versio

There was only ever a 6B GPT-J, you must be thinking of GPT-neo's for smaller sizes. GPT-J was the best of its kind for a long while but even just the 7b version of LLaMa soundly surpasses it in how well it follows examples to solve problems and do useful work like summarization, keyword extraction and a mini search agent. Being able to run something on your laptop that matches the original davinci GPT3 and can be tuned to go beyond is nothing to sniff at. The best models will be by API but there is a threshold of utility for LLMs, below which they're just bad story telling toys, that hasn't been available for home users until recently, with FlanT5s and LLaMas.