I think Jantzen shirts are far better than Brooks Brothers and the other brands you mentioned because they use single needle tailoring, troca/MOP buttons, shank-wrapping and crossover stitching in attaching the buttons, and they do pattern matching. I'm no expert, but I'd say that in terms of construction the Jantzen shirts are equal to or better than my Zegna, Brioni, and T&A (Turnbull uses double needle) shirts. The fabric is not particularly luxorious, but if you stick with the 120's or 140's they offer you should be fine. The kicker for me is getting to do your own styling down to very detailed levels. I don't think I could ever find a nice OTR shirt with a dual button wide 3" spread collar, split yoke, side pleats, turnback cuffs, constrating button-hole thread, and triple thick MOP buttons, let alone one that fits me.