That's an interesting question, really. They're fairly different stories, in both conception and execution. The Hobbit is basically a novel for kids that's easily enjoyable by adults, while LOTR is, in some senses, the reverse: a book for adults that can be enjoyed by kids. The Hobbit is sort of a traditional adventure story, a journey (quest) with lots of interesting happenings on the way, some of them fairly incidental but usually interesting. LotR is much more epic, the tone and style much grander (and more beautiful). The story darker, grimmer... more thematic, really, and with much more depth. The Hobbit is full of rhymes and riddles, the LotR is full of song and poetry. The Hobbit provides the first part of the story, but most of the necessary information is covered in the opening of The Fellowship.
Neither open particularly fast, it should be noted, particularly The Fellowship. It's not entirely without tension and interest, but it takes a number of chapters to really get into the heart of it (and if you ever read anything about the composition of the story you'll see why... the story changed greatly as he wrote it. The story started, really, as a sequel to The Hobbit, but it became something much more in the writing).
Does that help at all? It's all a riddle in the dark, really... and, yes, that's an insider joke. You'll get it soon enough... if you survive the journey :)