I think a lineless tileset could look good, it's that we just don't have any good ones yet. The current lineless sets are half-assed MSpain jobs, or "lets slap on some texture and call it a day".

I think aligning the tiles to the grid is okay if it's something manmade, like metal panels or bricks.

I prefer the old medivo style over the JJ2 one. After all, castles were made of bricks. Mediv2o brings out the best of both but I still think it could feel less tiley and more organic.