I have a nuvi 2460 and garmin express (version 3.1.8.0) does not display all the software updates that webupdater or mygarmin has. For example for voices. webupdater displays voice software for many different voices I do not have installed on my 2460 but express does not display the same voice software.
You'll find additional voices under the Device tab in Express when you scroll down. The difference is they're not listed individually, so English voices for example includes all the English voices, not just one, whereas WebUpdater or myDashboard list them individually.
