Vegemite is a lot smoother (which is a bit odd, considering it’s from the land of Ocker... wouldn’t you expect the Aussie version to be a bit horny-handed, while the Pommie version should be all Brylcreem and sleaze? National stereotypes aren’t what they used to be).
We had a national Marmite shortage here a year or so ago--they called it Marmageddon. Not a jar to be had for love or money for months. Didn't bother me any--can't stand the stuff--but it was a huge deal for many.