If you are using b6156 and it's working properly for you, then it's to keep it running.
We discovered some storage availability issues in ESX when updating from older DSS V6 versions.
If you have used an older DSS V6 version and after the update to b6156 you are facing some problems, you should downgrade to the older version to fix it.
If you made a clean install of the DSS V6 b6156 and you are facing any problems with storage availability in ESX downgrading to the older version won't help.