Dan,
We've always had Eriba Touring caravans, and whilst they have a rightly deserved reputation as one of the finest caravans for towing, they've never had shock absorbers.
That was until we bought our new Eriba Triton last year, which came with the upgraded ALKO 1200 kg axle and a pair of ALKO octagonal shocks - and the difference is quite noticeable.
Are they worth adding? Yes.
Also, shock absorbers are part of the mandatory requirements for "Tempo 100" in Germany - allowing German registered cars to tow a caravan at 100 kph rather than 80 kph.
Robert