As someone who has DMed this way many time and played as a player many times, I can distinctly say it is not nearly as cohesive. It has always taken more sessions to finish the campaign. The records for the "notekeeping player-type" are not nearly as clear or accurate. And the storyline waxes and wanes (which can be a really good thing). But it is not a misconception. If you have a series of scenes and settings, and everything in those are laid are plot related, as opposed to making something up, then the cohesiveness is clearer. It is almost more direct, which is not to some players liking. That's okay. To each his own.
I should mention we like our campaigns to last 4-8, four hour sessions. That's it.
That's a very clear answer. All adventure paths, as written, are railroads. All the more reason to get rid of the term. Because if a DM gives five options, and all five lead to separate, yet still "desired outcomes," then most of the people playing with WotC products are railroading.
Sorry, I am not understanding. Could you clarify? Thanks.