GPT-6.1 Sol

Pros: The biggest improvement for me is that it gets very close to Astra-level performance without Astra-level pricing. I can use it for serious coding, research, computer-use tasks, and long agent workflows without feeling like every run needs to be reserved for something mission-critical. The 1.05M-token context window is still a huge advantage. I can keep large repos, specs, logs, documentation, and a lot of prior agent work in context without constantly trimming things down. I also really like the new multi-agent support. Being able to let Sol delegate parts of a bigger task to subagents makes it much more useful for complicated projects where research, coding, testing, and analysis can happen in parallel.

Cons: The main downside is that Astra is still the model I would reach for when I absolutely want maximum capability and cost is secondary. Sol also no longer supports the none or minimal reasoning settings, so it is less suited to truly lightweight work than Luna.

Overall: Overall, GPT-6.1 Sol feels like the model I would use most often for serious work. It has the context, tools, reasoning, and agent capabilities I want, but the price is low enough that I can actually run it heavily instead of treating it like a special-occasion model.