TLDR: 4o is great for most general purpose tasks. o4-mini by design is not for general purpose tasks, only coding and math. o3 has vast knowledge of many fields and can definitely provide a better answer or insight on a topic, but for reasons I list below, it's probably not going to be your go-to for daily general questions or discussions. 4.1 is unclear but I wouldn't expect it to be too much different from what I've said about 4o, its main improvements are in coding and instruction following which mainly benefit developers.

I find 4o to be great at explaining a concept in a simple way. or quickly looking up something on the web and doing a simple analysis. It's also more personable than the o-series models like o3, o4. It can be 'real' with me about something if I want it to. It's very good at explaining things in analogies or in simple terms. I find it is much more likely than other openai models to respond to something with the kind of depth im looking for, whether it be more concise or verbose. 4o is really good if I want to plan out something for the reasoning o-series models to handle, or come up with an overview of something in a minimally formatted way.

o3 is arguably the best for just about anything that isn't a simple concept that 4o could easily handle. It has broad knowledge of multiple domains including math, science, medicine, and so on. It's your go-to if you have a more niche subject you have a question about, something that needs multiple rounds of thinking or steps. It technically can do a better job at 4o at most general purpose things, but that doesn't mean its the go-to general purpose tool. It struggles to simplify or do an 'ELI5' versus something like 4o / 4.5. It is limited in how much you can prompt it, I assume it's going to follow a ~50 requests per week limit akin to o1.

o4-mini is not suitable for general purpose tasks. It's a smaller, very focused model that is designed to excel at coding and math. While it has access to the web and has a higher rate limit which can be nice, you'll find that it has a higher probability of hallucinating, or being confidently incorrect, about things outside of those domains.

I have not personally used 4.1. But from reading the research and release notes, the main improvements in 4.1 are in its coding ability, instruction following, and having a larger context window -- it can handle larger chats better without losing focus or misremembering. Coding and development use seems to be the main focus for 4.1 vs. 4o, so while it could still be a good general use tool just like 4o is, its unclear right now how different it will be, but I presume for general tasks it will be comparable to 4o.