I have one and use 4 barrels. Works well, but i did have a problem with my first one. I was a bit heavy handed screwing on the pipe that goes into the top of the barrel and it split. Cost me another £4 to get a replacement. I genrally use about one co2 bulb per barrel but that will depend on how conditioned you are. We genrally use them to take away in the caravan. 5lt is a good size for a weekend and are easy to pack in the car. I agree they are a bit plasticy and would reccomend the more sturdy versioon which I bought after i broke the first one. All in all though genrally pleased.