The simple concept of redeeming vouchers at the checkout instead of always waiting for some offer that could be even better than the previous ones is the good thing about Cumulus compared to Coop Superpoints. And the supposed extra offers are nothing more than ordinary special offers, which are annoying anyway. This is where Aldi has the best concept: the product costs a fixed price, which in turn is the same price for everyone.
The simpler the better.