Snow's pretty goddamn dumb, but for my money Sazh at his worst is far more damning.
(Sazh in his serious-character-is-serious moments is fine, it's the comic relief pseudo-blaxsploitation that's painful)
I'm pretty much done the game now, save some grinding and the last optional superboss. I really enjoyed it, though it wasn't without its flaws.
The comparison to FF6 for linearity is fairly apt, though FF13 takes it farther in the 1st half, and there're a few other similarities, such as how it manages its characters (like FF6 there's no clear "main character", and like FF6 the focus shifts around the cast as the game progresses).
Gameplay-wise, I think the comparison to Crisis Core is poor (it's not an action RPG); the game I think its battle system most resembles is FFX-2, which is fine in my book, with a dash of a very streamlined FF12 gambit system. I found it consistently challenging and tactically interesting; very strong, IMO.
There are some weird constraints to it (you only get an arbitrary-seeming 6 slots for party-role configurations, and you often want considerably more) and a couple of stupid flaws (all 6 of those slots get reset whenever you change party members, and it's annoying and time consuming to put them back together). You could also make the case that the first ~half of the game, basically until the end of the Cocoon sequence, is more like a very extended tutorial, as it goes out of its way to give you different job combinations and lead characters before setting you loose on your own.
Plot-wise, it's a little bit on the obscure and unfulfilling side, with a novel but somewhat underdeveloped setting but consistently pretty good characters. I'll be interested to play it in English, though, since my Japanese isn't as good as it used to be and some of my issues there might be linguistically inspired.
I don't think calling Lightning a Cloud-clone is fair, for all that her role in the introduction is exceedingly similar. In fact, I'm not sure any of the characters have clear parallels in other FFs, and the game often develops them in unexpected ways. Other than Snow, I guess, he's pretty typical of his archetype.
I dunno. I don't have a great sense of what you like in games, m.c., but I definitely think it'll appeal to NEB, and I thought it was pretty excellent. Not the strongest title in the series (X or VI, I think), but no slouch.
