If you're enjoying FFXI I'd say no, give this game some more time. I guess it also depends on your schedule, I play both, not that I actually have enough time to play both, but I do play both none the less.
I went back to mostly playing FFXI because a bunch of my friends decided to take a break from XIV while SE (hopefully) fixes some of their major grievances. FFXI is chock full of really exciting content right now, XIV is still getting off the ground, decide what's more important to you. Are you more excited about defeating absurdly powerful monsters with ridiculously overpowered high level abilities and wrapping up the story of Vana'Diel, or are you more excited about exploring a new world at its beginning?
Then of course, if one doesn't jump out at you, try XIV, it's F2P for a while anyway.