I created a comparison myself, because I couldn't find one. It was for my specific workload, which is CPU-intensive, but could be useful for others, too. An important find was that what we are being sold are not "cores", but "vCPUs", which usually correspond to hyperthreads, on slow Xeons. Which means no performance to speak of if the machine is loaded, which it usually is.

My conclusion was to rent physical servers (I use Hetzner) and get great performance at a fraction of the price.

https://jan.rychter.com/enblog/cloud-server-cpu-performance-...