Hi Gary,
There was a comprehensive and independant review of stabilisers by the German ADAC motoring organisation in 2005? So it may have been the AL-KO 2004 that was tested - but:
Basically out of all those tested, the Winterhoff and the AL-KO came out on top, with the Winterhoff just edging ahead - but for the UK, the better availability and lower cost of spares for the AL-KO would probably skew it back in favour of the 3004.
For Tempo 100 in Germany - the legal permission to tow at 100 kph (60 mph), the caravan must be fitted with a stabiliser and both the AL-KO 3004 and Winterhoff WS 3000 are mentioned as good examples - if my reading is correct "Zus