While I agree simultaneous voice/data is ideal, how many people really hold that as a make-or-break feature? Or rather, how what percentage of iPhone owners rely on looking something up while on a call regularly vs occasionally?
While it is only an occasional use for me, it is imperative that I have this feature. When my wife calls me because she is lost, I can put her on speaker and pop open google maps. All I need from her is a cross street and I can get her on her way. This is a priceless feature for me I've used multiple times.