We ran with SATA drives - at the time SSD was still only being introduced.
I do not recall our read/write times on the drives, but it was a very reliable setup. We had a number of drives fail over the years, but with the hotswap ability, it rebuilt the image on the fly and never had an issue.
Here's some base information on the Raid-50. They say High Read and Medium Write. All I can really recall is that we had no issues with any server in those configurations.
We later moved to a RAID-1 for files & single SSD for Databases.
Of course, we also provided HOURLY backups - so there was limited data loss should we have an SSD failure. Thankfully, we never had one!
Artashes can speak to the reliability and the backup service when we had an issue on the HostingDiscussion server. I don't recall the length of time on the outage, but it was fairly minimal because we had those hourly backups.