Wow, I have to say that was a pretty stunning flight. The last time I put anything on the record about SpaceX was years ago, and it was not complimentary. But that was during their Falcon 1 days, when they were making the elementary mistakes. Now is as good a time as any to update the record and say that I find the progress of SpaceX since then to be nothing short of astounding. Full marks for making a giant rocket with next-generation capabilities, flying it successfully, and landing most of the boosters. Having participated in some of the less successful members of the Delta family, I can sympathize with the problems of building and flying very large launch vehicles.
Success criteria for a test flight are all about the data. It doesn't matter at all that the center booster didn't land safely. (It matters that the drone recovery ship was damaged; that's already production hardware and you want that to keep working.) It matters that SpaceX has data in hand that indicate whether the Falcon Heavy design predictions were met. You fly the rocket for the first time because you simulated all you can and bench-tested all you can, and the only way to get more information about whether the design works is to try to fly it.
