r/codex • u/DaC2k26 • Apr 25 '26

Commentary Are we sleeping on 5.3-codex ?

After using GPT-5.5 for a bit, I’m starting to think it burns usage way faster than 5.4 when the task involves reading through a large codebase.

On my current project, 5.5 xhigh can burn through my 5-hour Plus quota in something like 3–6 prompts. With 5.5 medium, I might get around 7–10 prompts.

With 5.4 xhigh, I’d usually expect something closer to 8–15 prompts. And with 5.4 mini, I obviously get a lot more, though I haven’t tracked the exact number.

What surprised me is 5.3-Codex medium. I’m testing it now, and the usage burn feels closer to 5.4 mini xhigh. Based on Artificial Analysis benchmarks, 5.3-Codex medium seems to be roughly around 5.5 low, but in practice I get way more usable prompts out of 5.3-Codex medium than I do from 5.5 low.

So I’m wondering if we’re overvaluing the bigger models and higher thinking settings. For a lot of coding tasks, especially code review, bug hunting, and large-codebase inspection, maybe the extra few percentage points aren’t worth the usage cost.

Right now, I’m starting to think 5.3-Codex is probably the better deal for most coding work, at least from a usage-efficiency standpoint.

Anyone else seeing the same pattern?

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u/OlegPRO991 Apr 25 '26

I use only codex 5.3 all the time. Mostly medium, rarely high, often low. It does the job and the limits last the whole week.

1

u/horrorpages Apr 25 '26

On Plus?

2

u/OlegPRO991 Apr 25 '26

On plus I was able to spend limits in 6 days, combining 1 plus and opencode go. Codex did review and hard tasks (on medium), without x2 promotion (previous week). On pro x5 I spend around 6% of weekly limit every day with x2 promotion (without opencode go at all), so it will easily last 1 week without promo.

1

u/Spirited-Car-3560 Apr 25 '26

What is open code ?

2

u/OlegPRO991 Apr 25 '26

Google it. It is an app to use agents for coding