I would like to add something to your post and in response to others.
First thing is that Yoshi already confirmed that they were working on an idea to add specific stats to gear pieces, like traits or set bonuses, this is a first step for the hybrid system of vertical/horizontal progression.
And last, i always keep seeing the use of BiS, and how this would mean illusion of choice more than real choice, what this people fail to understand is how BiS is applied almost exclusively to hardcore raid groups, who are a minority in this game, in general horizontal gear progression offers choices to players, to pursue pieces of gear with close values which offer slight advantages on pair with the difficulty of the content that drops it, not everyone will have the time, the static or the skill to gear the BiS, but they will still be competent to play all the contents even if they don't have the BiS.
Ultimately, there are always preferences for play-styles, so even if there's a BiS one could chose to go for a different set to make the play style more comfortable, like chose if you want gear to make mudras have shorter recast, or an increase in ninjutsu potency, a way to enhance the damage caused by nin dots or the critical damage dealt by melee skills, there will always be a BiS, but the capacity to get or not get it, and the choice to play on a more comfortable way will always be there as well.