GPT / ChatGPT.
Generalist speed, tools and agents, broad ecosystem, strong everyday default.

OpenAI · ~128,000 context
Strengths
Generalist speed, tools and agents, broad ecosystem, strong everyday default.
Watch for
Instruction hierarchy matters; quality varies sharply by model snapshot and tier.
Prompting
Separate SYSTEM rules from USER task. Prefer explicit schemas for structured work.
Primary sources