The comic are a bit darker in nature. You have also have to understand that they can put much more elements in a comic that a 22 minutes episode, since it's a lot cheaper and time consuming. They put continuity from the show in several comics, but it seems that the stories are what we could call "semi-canon": related to the past episodes, but with elements we probably won't actually see in the show. Which is too bad because some of them would be great in the cartoon. E.g. Luna has a possum as a pet called Tibberius. Also, princess Luna and Celestia personalities differ slightly from the show.



But you don't have to buy them individually since they sell them now as volumes and arcs. Go check Amazon.



As for being good or better than the show, you have to understand that it's not the same writers. Some are good some are so-so. The graphics can differ from another because the artist can be different from one to another. Now, there is the difference between the "Main" comic which is at #26 I think and the "Micro-Comics" series centered to a character and the "Friends Forever" which revolve around two. Or more (Discord and the CMCs for example). But if can't stand the drought of MLP cartoon episode, you could take it a peek.



You can watch some previews on the web. However, you can even read them all if you check (or Google) correctly. It is worth it.