Good analysis. I grew up in an evangelical church and still a member of this type of church b/c of family reasons but attend a conservative confessional Lutheran church every chance I get. The big box churches, as you call it, feel empty and hollow to me. Its like attending a live infomercial. Shallow and bad music followed by a slick sermon presentation. I prefer communion/creeds/ confessions of faith/rich and beautiful hymns with Christ crucified for our sins as the constant theme. Most people in my generation would rather stay home than attend something that is not entertaining.
what was funny for me, when I moved to Poland is that in Europe, Evangelical means the Lutherans, Evangelico-Augusburgo!