From the previous company I worked at (which used AWS infrastructure exclusively) and many others I've spoken to, IOPS were the leading issue when it came to AWS usage. Many insane solutions were proposed (such as RAID across multiple EBS just to maintain consistent disk performance), but for most use cases the only guaranteed solution was to move everything to RAM and assume disk is either stunted or useless.

My guess is that in the coming weeks, the infrastructure of the companies I spoke to will change substantially. The SSD instances are now the goto solution if you have a server up 24/7 and (Provisioned IOPS / EBS-Optimized instances) are for when you need burst infrastructure with good disk performance.

There are gaps in the AWS armour, but those gaps have been filled in at a consistent rate.