Similarly, we updated our model arena (52 apps each built by 26 models) to have GPT 5.6 Sol, Terra, and Luna today:

https://arena.logic.inc/

It's really interesting to see the Sol/Terra/Luna apps side-by-side.

I need to add these stats somewhere in the UI, but one interesting take away: Terra took 1/2 as much wall-clock time as Sol, but Luna took more wall-clock time than Sol (by about 23%). It's still much much cheaper, but it seems like Terra is likely a more optimal time/cost balance for most use cases.

The Terra quality is usually nearly as good as Sol, but much faster and cheaper. I do appreciate Sol's design sensibilities (see, for example, the audio sequencer). It's the first model in a while that is clearly distinct on that front. They'd all converged to very similar visuals for a while.

What caught my eye was:

            Model  Lines of Code  File Size  Gzip Size 
      GPT-5.6 Sol          1,264    35.5 KB    10.0 KB 
    GPT-5.6 Terra            827    20.0 KB     6.7 KB