Good article. I would just recommend to correct the title, as the Pi 400 is really not "much faster than a Pi 4", as the only difference is the stock speed of the Pi 400 is 1.8 GHz, just 300 MHz more than the standard Raspberry Pi 4.
What you might have said in the title, perhaps, is that the Pi 400 is much faster (roughly 40 times more) than the original Raspberry Pi.