There is not only difference in axis around which they go curved but also LG’s upcoming take on flexible display looks bit better than Samsung’s efforts. As you can see it curves in a perpendicular fashion and looks attractive in these leaked press photo.
LG had already confirmed about the flexible displays going in mass production and claimed to be the first manufacturer to do so. But Samsung launched the phone first!! Anyways, Lg G Flex will have a huge 6 inch display according to the source and may come in November.