OTOH, I found the SK policy for changes on short haul quite good. I think the fee is 600 dkk (used to be 500?) plus the fare difference. Basically if your original ticket costed more than 600, then it is always slightly cheaper to re-book than to buy a new ticket (in GO).
In PLUS, short haul, so far all my tickets were cancellable without a fee. So there the strategy is indeed to cancel, and to buy a new one.