For want of something better to do I have just been working out our ACSI Saving over a 9 week holiday in Germany and Austria this year.
Out of the 8 Campsites we stopped at this year.
2 Sites did not take ACSI one we stayed 3 weeks 10% discount and left caravan there for another week unoccupied at €2 night for Electrics for Fridge, while we stopped with the Thalers in the mountains.
The other one night was Belgium enroute home.
6 Sites Saved with ACSI €459.40 with £ at rate we got then £358.59.
The most expensive was €42 a night with ACSI €19 so excellent saving there.
We did not save quite as much as other years due to spending 3 weeks on non ACSI Site.
Verdict is Would not like to be without ACSI Camping Card.