Eh, AA4 is somewhat enjoyable, it has its moments, and in similar fashion to most Takumi's works, the cast oozes charm (Trucy, along with Franziska and Godot, is one of my favorites characters in the series), but the game is pestered with so many problems, some of those being HUGE plot holes, which in a story driven game can be fatal, that I can't wholeheartedly recommend it. It's from AA5 onwards that my problems with the series start to show.
But you are correct, if anything they should port them for preservation's sake.