I feel that we don't have enough options available to make our characters stand out from the rest or to customize them to fit our personal style. Let's say you have a L50 BLM. It won't be any different or play any different from any L50 BLM out there. It will be an exact copy minus the equipped gear.
Even when equipping spells from other classes, you are pretty much forced to chose the best spells to fit your job. So in the end you still end up with the same setup as everyone else and as things will go on, it will be like XI where you need a specific combination to play with others or they won't invite you.
Other MMOs out there have come up with systems that let's you tailor your character to your linking and still make it that you are just as useful in a group then other players from the same Class but with a different setup.
We have been asking for such a system from the beginning, there is tons of threads on the subject and Yoshi-P's answer was the job system. But that is hardly what we asked for, it is just an advanced job/class system a la Ragnarok Online or the advanced jobs in XI. Yes you keep the skills from your previous job but that is the only difference.
WOW for example has the talent tree, you can chose from 3 different play style for each job. A single job can then fit different roles in a group, from Tank to healer to DPS. It's your choice. This approach makes it that you have more options available to you when searching for team mates. If PLD and WAR for example are the only tanks and are not too popular, then you will have a hard time forming a group. Same thing for healers, if only one class is a suitable healer then it will be much harder to find one.
There are many different systems out there in other MMOs and i think that it is time for XIV to have it's own. Take ideas from existing systems or make one from scratch but i believe we need one if we are to have diversity and prevent the game from becoming like XI where you need the perfect combination to even play.