Hi Ben,
I can not remember the first time I visited the Dortmund show, must have been in the 80's
I have been there every Year since then, most of the time because our Club was there or I was Helping someone at the show, for example the past 10 years or so I have helped on the Deansmarine's stand..
I would say, yes it is worth the Trip... there are 8 Halls the size of football pitches to walk through and see models/miniatures of every thing you could possibly think about... from Fairgrounds, Fantasy Figures, Cars/Lorrys Trains, Planes/Helicopters, Boats..
over the years the Traders have been disappearing... I could be proven wrong this year..!