Nathaniel Whittemore

You heard some of that in the initial reactions, but some of the independent testers are finding that as well.

Entrepreneur Bindu Reddy writes, GPT-55 tops LiveBench.

It's an extremely good model on both benchmarks and in practice.

It tops benchmarks in most categories and is an insanely good instruction follower.

In practice, this makes GPT-55 better than Opus 4.7.

CodeRabbit writes, we've been testing GPT-5.5 in early access and are excited by its performance in code review.

In our evaluation, it delivered a more direct review flow, stronger signal, and better performance on the issues that matter most.

Headline result, 79.2% expected issue found versus 58.3% baseline.

Entrepreneur and engineer Flavio Adamo writes, Is GPT-5.5 better than 5.4 at code?

Yes.

Not because it suddenly turns every prompt into some magical perfect implementation, but because it seems to understand the shape of the request better.

It writes cleaner code.

It touches fewer things it does not need to touch.

It is less likely to over-engineer a simple change.

And most importantly, it feels like it wastes less time.

I think everyone who uses coding agents has seen this happen.

You ask for a small fix, and the model technically solves it, but it does so in the most annoying way possible.

It adds an abstraction you did not ask for, changes unrelated files, rewrites some logic that was already fine, and suddenly your quick fix becomes something you now have to review carefully because the model got a little too excited.

With GPT-5-5, I've seen less of that.

I do not know exactly how to explain it, but a model can be smart and still tiring to use.