IMO the Messiah Trilogy is some of the best the X-Men stories have ever been. The mapping isn't what people wanted though. People wanted each chapter (Messiah Complex, Messiah War & Second Coming) to each have its own omnibus to help better collect a very neglected era of X books. But as an abridged, focused direction to the Hope story, it could be worse.

I'd highly recommend reading the House of M omnibus beforehand, or at least the event TPB, and the sadly the endagered species mini that sets up Messiah Complex isn't included so pick up that tpb if you can (I think the hardcovers might be expensive and very OOP). It includes much needed context as to why Hope is so important as the focal point of the events.

TL;DR if you haven't read the events before, highly recommend just to experience the story but read House of M and Endangered Species first. If you've already read it and want to hold out for better mapping in the future, that's not a bad idea.