055 isn't in a permanent bleeding edge, it is not a new ship design anymore(12 yrs old). It's also a ship with rather expensive sensor suit, which is different from what 052D brings to the table.
052s are IIRC the only major warship class in the world with UHF array (though a few EU designs also have a biggie SMART-L, but it serves a very different main purpose). Which for obvious reasons is rather relevant in modern warfare.