the Oyashios are already highly regarded - so one would think that the japanese can continue to pump out an iterative improvementThe 2,900 ton class is not in service yet.
without going into verifiable detail, they are regarded as being the deepest diving conventionals in the world. At a design level, they are a legacy Barbel design - which is still regarded as the most acoustiucally sound and transparent base design ever made.
there are very few fleet sub designs using conventional power that could compete with them across a few parameters.