Is GPT-6-Sol just the newer version of GPT-5.6-Terra?

A user on Reddit questioned if "GPT-6-Sol" is merely a newer version of "GPT-5.6-Terra," noting that "GPT-6-Sol" seems less effective than "GPT-5.6-Sol." The user observed that "GPT-6-Sol" shares the same pricing as "GPT-5.6-Terra" and performs similarly, leading them to revert to using "GPT-5.6" due to its perceived superiority.

This user's direct comparison of GPT-6-Sol with GPT-5.6-Terra and GPT-5.6-Sol suggests the new version might not be an upgrade, unlike typical model releases.