Published on August 11, 2025.

Over the past few days, I’ve been testing GPT-4.1 and GPT-5 side by side in SuiteAnalyzer using the exact same dataset — an Income Statement, Balance Sheet, Cash Flow Statement, and Trial Balance.

The results?
• GPT-5’s responses are significantly more comprehensive and insightful.
• GPT-4.1’s responses are faster but less detailed.

In this post, I’ll share why that difference is expected, and which model I recommend for different use cases.

What I Observed

When fed the same financial data, GPT-5 consistently delivered:
• More in-depth commentary
• Better contextual understanding between different reports
• Richer analysis with actionable insights

By contrast, GPT-4.1’s responses were:
• Faster to generate
• Shorter and more surface-level
• Still useful for quick checks, but lacking GPT-5’s depth

I’ve included links to both sets of responses so you can compare them yourself:
• GPT-4.1 Analysis
• GPT-5 Analysis

Why GPT-5 Is Slower

This difference in performance isn’t surprising, and here’s why:
• Bigger Model, More Computation. GPT-5 has more parameters and deeper reasoning layers than GPT-4.1, meaning each token takes longer to generate.
• Longer Output Capacity. GPT-5 supports up to 128,000 output tokens, compared to GPT-4.1’s ~4,096. Even if you don’t use the full limit, the model’s planning process scales with its capacity.
• Deeper Reasoning. GPT-5 is designed to think through problems in more steps before responding, which improves quality but increases “first token latency.”
• Newer Infrastructure. GPT-4.1 has been optimized over time; GPT-5 is newer, and further speed improvements are likely as OpenAI fine-tunes its deployment.

Cost Considerations

Interestingly, GPT-5 isn’t dramatically more expensive than GPT-4.1.
• Input tokens: Cheaper for GPT-5 than GPT-4.1
• Output tokens: Slightly more expensive for GPT-5

If your analysis is prompt-heavy but output-light, GPT-5 may actually be more cost-efficient.

If you expect very long reports, GPT-5 may cost a little more — but the quality may justify it.

Advice for SuiteAnalyzer Users

Here’s my guidance for choosing a model.

Use GPT-5 when:
• You need deep, nuanced analysis
• You want connections drawn across multiple reports
• You’re preparing executive-level summaries or board reports
• Speed is less important than depth

Use GPT-4.1 when:
• You need quick turnarounds
• You’re doing exploratory analysis or rapid Q&A
• You just need a snapshot rather than exhaustive detail

Final Thoughts

In SuiteAnalyzer, both GPT-4.1 and GPT-5 are excellent models to consider — but they serve different purposes.

Think of GPT-4.1 as your fast, reliable analyst and GPT-5 as your meticulous, deep-dive consultant.

If you haven’t tried GPT-5 yet, I recommend running the same report in both models and seeing the difference firsthand. The extra wait time might be a worthwhile investment in insight.