I believe the step up from the Caldera to the Kula also provides you with a different frame. Up to the Caldera, most of the hard tails in that line are the same frame with differing levels of components. As I recall, though, the Kula provides you with a lighter frame plus better components. As far as if it's worth it... if you can afford the extra $300, yes it is worth it. If you cannot, then the Caldera is a nice bike as well.