Nice summary! However it is unfair to compare the state of a previously released version, with 3 additional patches or more (5.5), and the state of a preview engine version.
Or put it in another way: Let’s wait until 5.6.3 to see how it fares against 5.5.3… Which is a good rule of thumb anyway: Until at least 2 or 3 patch releases, I would never consider migrating to a new UE version.