We provide UpCloud as one of the cloud options for our SaaS database/metrics/messaging offering at Aiven.io and have been extremely happy with their disk i/o performance.

Here's just a quick "hdparm -t" test I just ran on two random low-end nodes:

upcloud-de-fra: 1028 MB in 3.00 seconds = 342.12 MB/sec

aws-us-west-1: 58 MB in 3.02 seconds = 19.17 MB/sec

I would of course recommend everyone to benchmark their actual workload on each cloud option before making the decision.