The Final Fantasy series has many strengths, but only some of them have strong storylines while others have great gameplay (typically noted as the even number ones being better with the former and the odd numbers being better with the latter).

I don't believe I've commented on that many JRPGs, but it is very important, IMHO, to note that Final Fantasy XIII isn't really a JRPG - part of the streamlining process involved removing the very things that separate a JRPG from a Japanese made adventure/fighting game, which is why it's reception among Japaneses fans is so mixed.

So I think it only fair to note that this game is neither an RPG or a JRPG, and that the intent (which has been confirmed by multiple interviews with the producers and game designers) was to make a new type of game.

Hence if you are a fan of RPGS or JRPGs in particular, you may not like this game, and IMHO you should definitely rent it first.

I give it a 7 out of 10, because it's not a BAD GAME. That's the important distinction. It's an average experience where the best parts don't quite measure up to other high points in the overall series, but it is very beautifully rendered and you may like it. I don't think many games should have a 10 out of 10, nor do I think a 9 out of 10 should be awarded every time a new game comes out.

I'll go through the negative marks to give you an idea as to why it's not higher:
-Combat system is not strategic nor dynamic, and in some ways works against having a smart strategy by forcing you to achieve conditions with pre-set "ideal" configurations. The player is often forced to adopt this "ideal" or be punished with fights lasting up to forty minutes before victory or quick defeats. In many ways, the stagger meter acts as a primary "HP" bar, in that you often need to pay more attention to that in order to deal real damage - this means that this is more of a button masher than previous games, and is a step back in some ways.
-The graphics can be inconsistent. You notice this more frequently when the game is rendered using the console to power the scenes versus CGI and/or when you notice that their fingers often look like lumps of weathered sausages.
-The civilization and the story is more realized through the codex than the actual depictions on-screen. Interestingly enough, this is one of the first games in which most of the questions on the Gamefaqs message boards are expressing confusion about what the story was about or what was going on rather than questions about the gameplay itself. Which is extremely odd and reveals a lot about the experience. I think most players really just got the impression that this was a "cutscene A -> cutscene B -> cutscene C -> cutscene D, etc" experience rather than a "game". It almost takes linearity to a new level of non-interaction. Even more annoying - there are CGI scenes showing the characters running, or preparing to fight, and then when the scene reverts to the map, the enemies are not in sight or are migrating along their pre-designed paths.
-This game is often not "fun"; this is more of a critique for the battle system, which is where you spend all of your time in between cutscenes. Like it or not, it can get exhausting to spend more time looking at the hp or stagger meters then really enjoying the battles and I feel as if you're never allowed to get into a groove where it ever feels organic or natural.
-The "Replayability Factor" is really low. Since the levels and the storyline progress in such a linear fashion, there is no reason to start a new game unless you didn't create enough saves to enable you to experience your favorite scenes.