Kill Team Elites has opened up a ton of new options for (almost) every team, and the Astartes may have gotten more new possibilities than anybody.
This former Tactical Sergeant picked up a pistol (I plan to run it as a plasma pistol, at least for now) by becoming a Company Veteran.
Elites has immediately changed what you can do in a Kill Team roster and team. The Space Marines no longer need to scrimp on the best weapons, as the veterans open up what amounts to unlimited access to special weapons.
Dark Angels did not get the same level of flexibility, as they cannot take Sternguard or Vanguard Vets, but I’ll see what I can do. For fluff reasons, I may move the Eremoi away from the First Legion anyway.