While this a beer topic - I make wine and use this device to fill my bottles, I have used it to fill some beer bottles with Hard Cider that I made.
This is the site for more info:
The problem that I found with the spring loaded fillers is that if I was distracted - I over flowed.
Sometimes I would pull out too soon, and not get a correctly filled bottle.
It was also very slow, because of the diameter of the pipe.
With the filler above - I can fill one bottle while I cork another one. Usually fills up before I have corked the wine bottle - fills up very quickly for a beer bottle.
These guys are around $30 (US)