Miles and more chargé full fuel surcharge and so makes the programme for short haul redemptions poor value generally, though in your case perhaps not given the fares available.
BA offer reward flight saver and they have effectively dropped the fuel surcharge on those flights with the fee being used to cover APD and airport fees. The down side is that these seats are only available when the lower fare classes are also available. Not withstanding the programme has improved immeasurably as a result for short haul redemptions in the last year or so.
I would have chosen DUS as th station is very efficient and well served by high speed ICE trains.