The 3-5-2 or 3-4-3 is good for pressing as we have more players higher up the pitch to win the ball in their half. I also think it is an effective antidote to 4-2-3-1. However, if a few teams are successful with 3 at the back as they seem to be, it won't take long before all those innovative managers in the Premier (and elsewhere) copy the latest fashionable tactic. Which will then partly negate the tactical advantage it offers.
for me, though, i think it is the best fit for our current players. We have 3/4 excellent CBs, and 3/4 potentially very good wing-backs - not as sure about Davies. And we have a target forward who would benefit from playing with another striker.
And a good choice of different types of midfielder - who are probably better suited to playing narrow.
What will be amusing is if lower league/non-league football goes down this route, as it probably will at some point. From from my limited personal experience as player and manager, 3 at the back is one of the toughest systems to get right, and as a striker I always enjoyed playing against three CBs as they invariably had problems sorting out the marking when they were defending attacks that came down the flanks.