After many moons have passed without me setting up a formal, strategic photo backup, as I have already sold my soul to google I thought, why not use their backup? Allegedly "unlimited" storage for 1600x1200 (ie, ok to look at) I've pushed the button.
24 hours and 15,000 into 120,000 images it seems to be working ok. Amusingly, it is backing up all my RAW files, by converting them to jpg, providing duplicates of each although the converted jpg is more lossy and lower quality than the reduced in camera jpg.
Organisation wise, there is a folder structure, only the maximum granularity is a year, which is a shame, the date is from the EXIF as expected, rather than the folder it comes from.
So, a handy painless backstop against losing it all, but not much use for serious organisation. I wouldn't consider using it for a serious archive.
ETA - found the "Don't back up RAW file setting" now