ChatGPT's model 4o is still missed by a devoted faithful. Its new model, 5.5, is bringing hope that some of its old spirit might be back. Jaap Arriens/NurPhoto via Getty Images When OpenAI shut down ChatGPT 4o in February, its biggest fans were heartbroken. They thought it had the best personality among ChatGPT's recent models, and still mourn it. With the release of ChatGPT 5.5, the newest model is showing some of that old spark. For some ChatGPT users, February 13 was dark. That was the d...