Considering one myself at the moment a 570 vs. an AyA No.4/53. The Arrieta is a side lock and has a much nicer finish and attention to detail but at double the price of the AyA. My only concern with the Arrieta is what appears to be degradation of the wood around the side plates. It appears as if the annual removal of the plates/locks has worn the edges of the stock. It kind of bothers me for $4-5K.