For true beginners, the nuance is not decisive so I wouldn't worry too much about it due to "analysis paralysis" and just make sure that it's at least a 1 for 1 trade.
That being said, I once knew a 1100 who pretty much always took Knights off the board with his Bishop just because he hated being tricked and forked by the Knights. This would be a positional mistake in many situations for higher rated players (pawn structure dependent) but for lower ratings, it's not as big of a difference maker.
Personally, I prefer the Bishops however I also play the Ruy Lopez Exchange Variation which gives up my light squared bishop for black's c6 knight very early on (move 4!) but the compensation is pawn structure damage on the queenside and a pawn majority on the kingside.
I personally think knights are better because you can't block a knight check and it forces the opponent to move their king which can help in a lot of attack sequences.