A few things to consider:
1) AMS Is a more pleasant connecting experience than CDG if that is important to you.
2) As mentioned above, KL and AF are not really comparable for "premium economy" because they are very different hard products. Of the two I would choose AF PE every day.
3) If you fly AF in PE, avoid the A380, the cabin is not very nice.
4) Spain is often a good value for business fares...if you be patient, you might be able to get one seat on cash and one on miles for the same "price" as two PE or coach tickets.