It took us (the Irish) a long time to get used to drinking anything other than 500ml beers in Germany, but once I had lived there for a few years it would have been unthinkable to go over a "null dreier" 0.3l beer when out on a nights drinking.
Main plus points were you always had a fresh beer to hand and being a stemmed glass the beer didn't get warm as you got to the bottom of it.
The 0.1l was considered by all Germans to be a granny beer, and they'd drink that with their dinner( grannies that is.)
I'd not be bothered by a change in size personallly, but at home I do drink from pint glasses mostly.