Installation on a cloud GPU
I installed ComfyUI on my HK server with a single GPU. The repo comes with a `run_nvidia_gpu.bat` for Windows and `python main.py` for Linux. The real work is downloading models. You need at minimum: a Stable Diffusion checkpoint (SDXL or SD3, 6GB), a VAE, and optionally ControlNet models. I downloaded 5 models totaling 35GB. The first run took 3 hours because I had to hunt down missing dependencies (xformers, onnxruntime, etc.). The ComfyUI Manager plugin helps but is not a one-click solution.
The node graph is the killer feature
In ComfyUI you do not type prompts into a text box. You build a graph of nodes: Load Checkpoint → CLIP Text Encode (positive prompt) → KSampler → VAE Decode → Save Image. Each node has input/output pins you connect with wires. This visual pipeline means you can do things that are impossible in Midjourney: use one image as a style reference (IP-Adapter), another as a pose reference (ControlNet OpenPose), and a third as a composition reference (Canny edge). For the saas.pet review headers, I loaded 96 tool logos as reference images and generated matching hero images with consistent style.
Batch generation saves real money
Midjourney Pro at $60/month gives about 200 fast generations. ComfyUI on a $0.50/hour GPU instance generates 400 images per hour. For the saas.pet project I needed 200 review header images. ComfyUI did it in 30 minutes for $0.25 of GPU time. Midjourney would have taken 2 days of manual prompting and $30 in subscription cost. The tradeoff: ComfyUI requires you to set up the pipeline once, which took me 2 hours to get right. After that, you just swap the reference image and hit Queue Prompt 200 times.
The learning curve is real and steep
I spent the first 6 hours frustrated. Nodes did not connect, model formats were wrong, the output was black squares. The documentation is spread across Reddit, YouTube tutorials, and random GitHub discussions. The ComfyUI Manager plugin helps with model downloads but the core workflow concepts (what is a VAE, what is a KSampler, why is my latent space exploding) require real learning. I watched 4 hours of YouTube tutorials before I could build a workflow from scratch. If you just want pretty images with minimal effort, use Midjourney or DALL-E.
When to use ComfyUI vs Midjourney vs DALL-E
Use ComfyUI when you need: batch generation (50+ images), consistent style across a series, ControlNet for precise composition, or you have a GPU and want zero per-image cost. Use Midjourney when you need: the highest quality out of the box, creative exploration with minimal effort, or you do not have a GPU. Use DALL-E when you need: API integration (via OpenAI), text rendering in images (DALL-E 3 is still the best), or you are already paying for ChatGPT Plus and want it included.
