Ahead of the holidays, Microsoft said it was upgrading the AI model behind Bing Image Creator, the AI-powered image editing tool built into the companys Bing search engine. Microsoft promised that the new model the latest version of OpenAIs DALL-E 3 model, code-named PR16 would allow users to create images twice as fast as before with higher quality.But it didnt deliver. Complaints quickly flooded X and Reddit.The DALL-E we used to love is gone forever, said one Redditor. Im using ChatGPT now because Bing has become useless for me, wrote another.The blowback was such that Microsoft said itll restore the previous model to Bing Image Creator until it can address the issues. Weve been able to [reproduce] some of the issues reported, and plan to revert to [DALL-E 3] PR13 until we can fix them, Jordi Ribas, head of search at Microsoft, said in a post on X Tuesday evening. The deployment process is very slow unfortunately. It started over a week ago and will take 2-3 more weeks to get to 100%.So what went wrong? Its difficult to compare model outputs from anecdotal reports, particularly when the prompts arent standardized. But many users said that PR16 tended to make images look less realistic and lifeless. Mayank Parmar, writing for Windows Latest, noted that PR16-generated images lacked detail and polish, and appeared weirdly cartoonish. Its not the first time an image model that presumably passed internal checks wasnt well received publicly. Back in February, Google was forced topauseits AI chatbot Geminis ability to create images of people after users complained ofhistoricalinaccuracies.The missteps illustrate just how challenging it can be to measure model improvements in the real world. According to Ribas, Microsofts benchmarking found PR16s quality to be a bit better on average compared to the previous Bing Image Creator model.Whatever internal metric the company used, it seems clear that it didnt align with most peoples preferences.