Comment by surajrmal
8 hours ago
What benefit is there to sticking on older models? If the API is the same, what are the switching costs?
8 hours ago
What benefit is there to sticking on older models? If the API is the same, what are the switching costs?
Consistency, new models don't behave the same on every task as their predecessors. So you end up building pipelines that rely on specific behavior, but now you find that the new model performs worse with regards to a specific task you were performing, or just behaves differently and needs prompt adjustments. They also can fundamentally change the default model settings during new releases, for example Gemini 2.5 models had completely different behavior with regards to temperature settings than previous models. It just creates a moving target that you constantly have to adjust and rework instead of providing a platform that you and by extension your users can rely on. Other providers have much longer deprecation windows, so they must at least understand this frustration.
If you're trying to run repeatable workflows, stability from not changing the model can outweigh the benefits of a smarter new model.
The cost can also change dramatically: on top of the higher token costs for Gemini Pro ($1.25/mtok input for 2.5 versus $2/mtok input for 3.1), the newer release also tokenizes images and PDF pages less efficiently by default (>2x token usage per image/page) so you end up paying much much more per request on the newer model.
These are somewhat niche concerns that don't apply to most chat or agentic coding use cases, but they're very real and account for some portion of the traffic that still flows to older Gemini releases.