OpenAI renamed GPT-5.6's tiers โ Sol, Terra, Luna and this time the names actually tell you something instead of making you decode a version number โฌฉโคSol โ the flagship, priced accordingly. Hard coding, security work, multi-step problems. โฌฉโคTerra โ the everyday one. Roughly half Sol's cost, fine default for most business stuff. โฌฉโคLuna โ cheap and fast. Summaries, drafts, the routine stuff nobody wants to pay flagship prices for. It's similar to Claude's Opus, Sonnet and Haiku The interesting bit is a comparison someone ran: a full day testing Sol against Claude Fable 5 on actual tasks games, websites, coding, brainstorming not benchmark screenshots Fable came out ahead creatively Better games, better site designs, more polish, more willingness to push back on a bad idea instead of just executing it Sol came out ahead on speed and cost, no contest One project: Sol did it in 7 minutes for about a dollar Fable took 20 minutes and almost $20 for a comparable result Which one's better probably isn't the right question It's what you're optimizing for that day Fable if you want the strongest output and don't mind paying for it, Sol if "good enough, fast and cheap" actually is good enough Feels like the obvious move is using both: Fable to think it through, Sol to actually build it