I ran the same prompt that I used with Fable 5 (altering it just to say "Opus 5 Did This" on the screen) and the same custom frontend-blender skill I created, and asked Opus 5 to attempt the test at creating a Mac. This took Opus 5 about 52 minutes and took Fable 5 about 37 minutes.
The Fable 5 result, prompt and skill are located here: https://www.reddit.com/r/accelerate/comments/1uwrj86/fable_5_blender_make_a_mac/
Some notes: Even though it wasn't in the prompt (in fact the prompt said magnesium finish not black), it opted for a more modern black Mac M5 than Fable. Fable skipped making a logo on the back, and Opus 5 made a mangled version of the logo on the back. Also, Opus 5 printed letters on the keys and Fable didn't.
I'm planning to redo this experiment next with Kimi K3 and see the difference.