Just resumed some download workflow with cdsapi that I set up and successfully ran last year, only to find out that it did not work. Traced it to the need to install new api keys (which appear to be the same for everyone, so why bother?). However, the code just throws 404 errors (Not found for URL), no hints that it may be the api keys. You also need to “(re-)Accept terms” per dataset (for data that is full, free and open!?). Rather annoying.
When finally done, you wait order of 10 minutes to get a [small] sub-selection of parameters. Not exactly modern-day Big Data access. But alas, I guess it keeps the massive downloaders at bay, so eventually benefits “the user”.