This year uefa champions league round of 16 is not tough, the only tough matches in the round of 16 are Barcelona vs Napoli and Atletico Madrid vs Inter Milan. I see Borussia Dortmund winning against PSV because Dortmund is more experienced than PSV in the uefa champions League, and Borussia Dortmund topped the group where clubs like PSG and AC Milan are.
The matches for the round of 16 have not yet started because all matches for the Champions League will resume in mid-February even though many people have made predictions from now on. You may say that Borussia Dortmund is more experienced in the Champions League than PSV, but this season there could be quite different results because PSV is also quite strong this season so Borussia Dortmund cannot be careless with the experience they have.