Just got back from passing my GCP Cloud Architect Exam, what a relief! Big, big thanks to Linux Academy and Matthew Ulasien for the excellent GCP courses provided here.
I can't remember whether it was mentioned here but I think it is worth emphasising even if it was: If you're thinking of sitting your exam and you haven't already, read the case studies provided by Google. Read them again and again. Once you have read them, watch the Google video on cloudconnect.goog "Deconstructing a Customer Case" to hear Google Engineers breaking down these very case studies. It helped me to print out the case studies, highlight parts, scribble notes of scenarios and products they could use. This will all be invaluable knowledge when you get to the exam as a lot of it refers to these case studies and if you know them well, you'll already have a good idea of a lot of answers.
If you take Matthews GCP courses and know the case studies inside out you'll be just fine come exam time. Good luck people! :)