v2 is a complete rewrite of the bash script from v1 in Go. This is easier to maintain and extend, and brings down the image size to less than 15MB (as compared to 100MB with v1).
Updating from v1
v2 is almost entirely compatible with v1 with one breaking change:
MC_GLOBAL_OPTIONS has been removed
As v2 does not consume the mc MinIO client anymore, there is no way to pass global options to its invocations anymore. If you were using this option, you can now set AWS_ENDPOINT_INSECURE="true" if you were relying on such behavior (#1).
All other options from v1 are still supported as is, so in these cases you can update the image in use without any further actions required.