Flying being set aside, do you like the actual achievement of Pathfinder?
It gives you a list of goals and things to do in the game, and to me, it is very satisfying completing those goals and activities. Flying is just the side effect of completing the achievement.
I hope in the next expansion, they add more interesting things to complete in the pathfinder achievement. Maybe if it is a part 1 and part 2 achievement, the part 1 reward could be some teleportation device to teleport to key areas around the new zones, kinda like the Argus ports. Then part 2 would be the unlocking flying part half way into the expansion, preferably a year or more into the expansion.
All in all I think the Pathfinder achievement is a fun, goal oriented achievement, and it definitely keeps me doing things in the game
Some ideas that can be included as part of the achievement could be:
- add collect xyz number of new pets in the new zones
- complete xyz number of heroic / mythic dungeons
- complete a fun quest chain spanning tens and possibly hundreds of quests
- get attuned to xyz mythic dungeon
- kill 50 unique rares in the new zones
etc stuff like that would make it even better and more interesting imo.