1) It cuts a great big chunk of fat from the series.
2) The "No. I am your father!" spoiler remains intact.
3) Anakin's entire backstory is treated like a flashback, which gives his ultimate fate in Return Of The Jedi a more immediate impact.
4) It raises the stakes for Luke's story, showing the audience what could happen to him if he chooses poorly.
The Machete Order is a fantastic way to catch up before The Force Awakens. I recommend it. I'm also very jealous of it. I should have been able to come up with it myself as a quick fix for the series' woes. It seems so obvious now. So, in an embarrassing and very insecure effort to top someone else's great idea that I felt like I should have had first, I tried coming up with my own Star Wars viewing orders to see if they could be better than the Machete Order.
Are mine any better? Let's find out ...