And on that specific kind of software, ultimately a big CRUD, there really isn't that much of a difference between GLM5.3 and Opus/OpenAI.
You see the differences when you get to different class of software.
I also have data entry applications that use LLM to actually parse documents, it's all Chinese models self hosted because the economic calculus beated a hosted API by about 5x
For mobile apps, I find that nowadays with Opus 5.5 the UI looks better, the UX is better, it can implement more tricky animations and gestures, and it can do all of that with far fewer iterations and feedback than eg. GPT 5.5 would have required.
Also vision capabilities were improved significantly with GPT 6 Astra or Opus 5.5, even compared to GPT 5.6 Sol.
There was no way the old models such as GPT 5.4 would have done a comparable job when asked to align an implementation to a visual reference.
Even for basic websites with no interactive functionality, this should make a significant difference.
I think use cases are the real reason why people have such different experiences, I too find that Opus5.5/Astra/6 are better for UI/UX now, it wasn't the case a year ago, at some point Gemini pro 3.5 was the best one at that.
That's also why I use all of them and try to not be locked to a single harness as well.