We've been twice to De Kempervennen. I think it was about a third cheaper than UK.
The swimming pool is pretty much the same (ie the dcs love it and I hate it), but there's no spa.
There's a ski dome on site which is run by a separate company, but you can do lessons there.
Also a lake with otters which they feed every day.
We played the odd game of badminton/ table tennis/ football/ crazy golf, and there might be archery, but I don't think it's quite so geared up to constant entertainment like the UK ones seem to be.
We spent most of our time ski-ing and swimming.
One thing which struck me: as with other continental countries, people seem to be happy just to be together as a family, so we found the atmosphere more relaxed.
Also, how can I put this, not so much 'sportswear as casual clothes' in evidence.