You know what, I think that both Abyss' and Symphonia's positives cancel each other out... While Abyss beats Symphonia in terms of characters, story, and battle system (love the free movement)... Symphonia was executed much better technically (almost zero load times, much cleaner graphics). But how could anybody defend Abyss' dungeons? They almost all looked the same and most didn't have much in the way of puzzles. Puzzles in dungeons make the Tales games, for me. Only a few were satisfying, namely the laaarge radiation gate dungeon. Boss fights in Abyss were extremely easy, apart from the first time you meet Legretta, and of course the secret boss... whom I came so close to beating, but then never went back to beat.
I haven't played Legendia but I want to, just to see what kind of a trainwreck it is.