Thats great feedback - thank you! I would then assume most people would end up using open source models as they tend to be cheaper with faster inference
The main reason is that the APIs represent an excellent cost / performance / complexity tradeoff.
Every project has relied primarily on the big models because the small models just aren't as capable in a business context.
We have found that Gpt4o is very fast, when that's necessary (often it's not), and it's also very cheap (gpt4o batch is ~96% cheaper than the original GPT4). And where cost is a concern and reasoning doesn't need to be as good as possible, gpt4o mini has been excellent too.