It'll be interesting to benchmark these against existing instance types. Also, there hasn't really been anything in AWS for low sustained load but these seem to fit the bill perfectly.
Yea, I think the fact that it even has a medium instance type is the biggest win for apps that don't need a lot of RAM. c5 and m5 start at large with 4GB/8GB respectively.
To me the most interesting thing will be comparing against t3, which gives you a surprising bang for your buck in scale out workloads, even when you factor in the fractional baseline credit allocation.
