I played Xenogears on PSP a couple years back. I imagine it helped that I played it portably, but I really enjoyed it. Yes the story is extremely convoluted with those random nouns that are a hallmark of Japanese writing (Lambs), but in my opinion that's part of the charm, and no game does it like Xenogears does for better or worse.
The game goes to so many places and your story objectives never stay the same for long. It's story driven and often railroads you through the areas with no way back because it wouldn't make sense in the story. Whereas your traditional RPG tends to be more about opening up the world map as you walk from town to town.
The battle system was carried by it's novelty and managed to hold my attention for the length of the game, but I feel like a hypothetical Xenogears 2 would really have needed to shake it up to keep it interesting for another 80 hours.
My main gripe would be the platforming. An RPG with a jump button isn't something you see everyday, but I remember some segments that were needlessly hard with having to hold down the run button and then time your jump properly