There are pretty direct parallels here to Android phones. If a mobile phone uses 'stock' Android (e.g. the Nexus One or Galaxy Nexus), then it's pretty trivial

There are pretty direct parallels here to Android phones. If a mobile phone uses 'stock' Android (e.g. the Nexus One or Galaxy Nexus), then it's pretty trivial to get an upgrade to the latest release. If you buy a heavily-customized Motorola phone, however, you may never see that upgrade because of the 'tweaks' that Motorola made, which they might not care to port forwards.