Midjourney is the strongest fit for sourcing brand-consistent illustrations and diagrams, as its style tuning and --sref style reference feature let you lock in a visual identity and regenerate matching assets across every blog post and presentation. You describe your brand look once, then iterate quickly to get polished, cohesive results at a low entry price. Ideogram is worth considering if your visuals need accurate text labels embedded in the diagrams. DALL-E works well if you are already in the ChatGPT Plus ecosystem and want a seamless, no-extra-subscription workflow. Stable Diffusion is the best pick if you need full control through self-hosting and want to fine-tune a model on your exact brand assets at no ongoing cost.