I disagree with you both on the Champions' Ballad being underwhelming. Master Trials I get, but Champions' Ballad featured 16 very well designed and clever shrines, and a dungeon that is seriously up there with some of the best in Zelda history. Overall, I'm satisfied with the content, I just wish they let me get rid of the dumb extras.
I agree that the Shrines are great (haven't get to the Divine Beast yet), but after completing the other 120 I expected something a little bit different. Also, I agree with the OP that the armors should have been rewards for doing more interesting NPC's side quests instead of that boring and repetitive "go here open that".