I must admit i haven't played all of the suikoden games, actually just 4 and 5.
I will give you my own impression of the game in brief
+ beautiful soundtracks + beautiful graphics + plenty of characters to discover + you command your own ship and it is to some extent customizable +great story + no bugs or annoying glitches + plenty of funny mini games
+ might be a cheap buy now since it isn't a new game anymore
- story is way too short - some random encounters can be quite annoying, especially if you have to travel to far away places - very linear storyline, you cannot make any decisions that will have an impact on the story - should have some more places to discover - the main character as well as the others actually have a story that isn't very developed in the game itself - you might need to grind to develop characters you could recruit only late in the game which might become quite boring during lack of places and story