Hello,
Great question!
If you are looking for "known bugs" in a certain code version or to see if a bug is fixed in a certain version. You should look at the release notes. In there, there are two tables "resolved issues" and "known issues"
Deciding wether to upgrade to a knew code you really have to make a choice if the "resolved issues" outlined in the release notes out weight the impact of the "known issues" in the document.
New code is released to patch bugs and improve the system which is why i tend to upgrade to the latest code ASAP, but that is a personal preference.
Certain/most codes undergo thorough testing and if they pass aruba "test procedure" they will be marked as a conservative release. It is always reccomended to go to the latest conservative release which you can find on the aruba support portal under the "conservative release" folder for the product you are looking for.
Any questions please let me know.
Thanks