I didn't play FF XI, but you could play as a job and a secondary job only, right?
I prefer the style of FFXIV where you can play as all classes/jobs with the same character and cross class skills. I'd like a way to change roles in the game, like if you were a GLD and use a MNK crystal to change to DPS or a WHM crystal to change to Healer. It would have obviously bad choices, like choosing a INT char to use a STR crystal, but some combos would be awesome! It could really help with future solo content. There's that balancing issue though...