According to Anandtech, Google managed to resolve the bug in the Android 4.3 update. The bug basically meant that the Nexus 7 had trouble dealing with storage, as it could not handle deleted storage properly. As a result, the tablet could not handle accumulated garbage and slowed down after users installed and deleted a lot of apps and content.
Android 4.3 has support for fstrim, and application that trims blocks not used in the file system. This lets the OS tell the SSD and eMMC controllers that a particular block is no longer in use and can be treated as garbage. In previous Android versions, the OS would register the blocks as deleted, but they would still contain the data and the controller would treat it as valid data, until it was overwritten.
It is not a gimmick. Our Nexus 7 received the 4.3 update last night and we are happy to report that it feels a lot faster now. Since we weren’t expecting any big changes, we did not run any tests prior to the update, so we can’t put a number on the gains. However, the tablet feels a lot more responsive, especially in storage intensive apps.
Other than that, the update is largely cosmetic and we won’t do a full review of Android 4.3. We tried it out on the Nexus 4 and Nexus 7, but there is not much to report, apart from the noticeable speed gain on the Nexus 7.