I've enjoyed Little Dorrit quite a lot more than I've enjoyed some other Dickens novels, Bleak House in particular. Sure, Little Dorrit is arguably less funny than the others, but it's also richer, and more tragic. I particularly liked the descriptions of Marseilles and Rome and Venice: they are not the rich, glamorous places they often are seen as, but instead they are every bit as bad as London: Venice smells of bilgewater, the roads to Rome are lined with empty villages, and Calais is filled with bullying Frenchmen. (Actually, this last may be simply racism.)
However, I've now read four Dickens novels and they all seem to have the same heroine: meek, self-sacrificing, dutiful, never a human (which is to say, selfish) thought in their heads. The only difference between Little Dorrit, Florence Dombey, Esther Summerson and Lizzie Hexam seems to be their backgrounds, which, diverse as they are, somehow manage to produce exactly the same person.
Plus, you can guess who Little Dorrit will marry from the beginning of the book.
But the supporting characters are the usual joys: Cavaletto highlights institutional racism; Pancks reveals unexpected depths of character; and there is a shocking suicide.
All in all, then: a pleasing novel with some excellent points to raise.