Reitse Eskens continues the comparison:
My last blog was about the Hyperscale tier, this week we’re back at more regular designs with Business Critical. This design is aimed at performance, local SSD storage and better CPU’s. But that’s not all. Besides this high-speed design, it also has high availability implemented by having a secondary replica ready to take over when the primary fails for any reason. And not just one but three replicas. So, your data should be accessible at all times. To make it even better, you can make one of these replica’s the read-only replica for reporting purposes. I’ve tested most tiers, again I didn’t test the 80 cores SKU because of the price. I also did some testing with and without replica’s but there wasn’t much of a difference. But again, my testing setup is quite simplistic, for your heavier read and write loads it might make a huge difference.
Read on for this and see how it compares to some of the other Azure SQL DB tiers.