I would love more horizontal progression, specially since the stuff we can get is limited by an imposed cap rather than a "natural" progression (weekly cap). Giving players more to do than just the same stuff, like roulette or raid until you can't get a reward from it. You know you have to do 450 tomes of the top tier tomes + the current raids or primal. That's it.

FFXI has situational gear that can be swapped on the fly (i.e. gear to enhance an ability, PDT, Acc, TP, etc.). So horizontal stuff made sense. In FF14 that aspect is hardly touched. You have the latest raid gear, the average tomes gear, and the materia upgraded gear. This gear is getting pushed away by the next iLv increase. So you get a very repetitive task.

The challenge the dev team has with 14 and horizontal progression is to make new rewards attractive. It doesn't have to copy FF11 at all. It just has to make sense for a player to get that kind of reward so that it can be used across the game.