Thanks! This is a very important detail which isn't documented anywhere: Retries are likely to succeed. A service where 1% of requests fail but failures are completely uncorrelated is far more usable than a service where 0.01% of requests fail but they keep on failing no matter how many times you retry them.
Additionally, assuming your block data is being hash-addressed, i.e. not changing the S3 objects once they are in S3, adding CloudFront in front of your buckets may go a long way to increasing that percentage.
I had to read these sentences a few times to understand what you were trying to say: "You now have the choice of three S3 storage classes (Standard, Standard – IA, and Glacier) that are designed to offer 99.999999999% (eleven nines) of durability. Standard – IA has an availability SLA of 99%."
No availability is mentioned for the others, but I assume it's 100%? Perhaps a simple table could help readers to scan and visually compare the values of two properties across three service classes?
When choosing between standard and this it would be helpful to understand the pros and cons. With the current description (below) it's as if the difference is only in pricing. But I assume there is a technical difference as well.
Also, the availability number could be explained better -- why is it different.
Standard - IA offers the high durability, throughput, and low latency
of Amazon S3 Standard, with a low per GB storage price and per GB retrieval fee.
If a GET fails, just retry as usual (most higher-level libraries do this automatically, sometimes with a backoff mechanism).