I'm not sold on diffusion models.

Other labs like Google have them but they have simply trailed the Pareto frontier for the vast majority of use cases

Here's more detail on how price/performance stacks up

https://artificialanalysis.ai/models/mercury-2

I’d push back a bit on the Pareto point.

On speed/quality, diffusion has actually moved the frontier. At comparable quality levels, Mercury is >5× faster than similar AR models (including the ones referenced on the AA page). So for a fixed quality target, you can get meaningfully higher throughput.

That said, I agree diffusion models today don’t yet match the very largest AR systems (Opus, Gemini Pro, etc.) on absolute intelligence. That’s not surprising: we’re starting from smaller models and gradually scaling up. The roadmap is to scale intelligence while preserving the large inference-time advantage.

This understates the possible headroom as technical challenges are addressed - text diffusion is significantly less developed than autoregression with transformers, and Inception are breaking new ground.

I changed my mind: this would be perfect for a fast edit model ala Morph Fast Apply https://www.morphllm.com/products/fastapply

It looks like they are offering this in the form of "Mercury Edit"and I'm keen to try it