I tried my simple Ionic app as well as the conference app.
On my Nexus 6p, it takes about 2-4 seconds to load up (mostly black screen, the flash screen goes away almost immediately). This is with --release and --prod, otherwise it takes way longer.
On my older Samsug Exhibit 4g with Android 4.2.2, all I get is a few seconds on the black screen, and then the splash screen - forever. These are the specs:
Is this type of behavior expected? I did see in the release blog post about Ionic 2 that it should be much more performant now. My Ionic 1 app is slow, but at least works fine on the Exhibit 4g.