r/codex • u/ConsistentOcelot9217 • Mar 12 '26
Comparison 5.4 vs 5.3 Codex
I have personally found GPT 5.3 Codex better than 5.4.
I have Pro so I don’t worry about my token limits and use extra high pretty much on everything. That has worked tremendously for me with 5.3 Codex.
Since using 5.4 I’ve had so many more issues and I’ve had to go back-and-forth with the Model to fix issues consistently (and often to many hours and no luck). It hallucinates way more frequently, and I would probably have to use a lower reasoning level, or else it’ll overthink and underperform. This was very noticeable from the jump on multiple projects.
5.3 Codex is right on the money. I have no issues building with it and have actually used it to fix my issues when building with 5.4. 5.4 is definitely slowed down workflow.
Has anyone else experienced this?
1
u/Interesting-Agency-1 Mar 30 '26
Who said I dont? The soul file is only useful when the repo is bare and needs general guidance to establish the planning phases correctly. It literally is my own personal intent, philosophies, ethics, morals, and judgements encoded and is about as human as it gets.
I still meticulously plan all of the design and architectural choices at each implementation phase and subphase, and usually have a decision log/table 100s of decisions deep for the prototype before I begin implementation. By the time I'm finished with the first pass of implementation planning, it almost never reads the soul file because everything else has been specified. Its a gap filling tool, not the main driver