Is the new UI system still not recommended for mobile? (Unity 5)

So, back in 2014 the mighty “Mike Geig” did this live training session on mobile development, in the middle of the session he discouraged the use of the old GUI system on mobile because reasons. (Drawcalls i think)

This also applies to the new UI system? I mean, a lot has changed, but is the UI still not efficient for mobile?

The new GUI system is fine for mobile use. The old system was an immediate mode GUI which was incredibly costly to use in a real application.

The new system however works far more like other systems, where textures are mapped to physical meshes in the scene which don’t need to get rebuilt all the time. As @fafase points out, there are techniques that can make use of the new system more optimal for maximum performance, however in general you should not worry about using the new UI system on mobile.