I, honestly, never experienced a "pacing" issue. I was actually kind of disappointed with how quickly I leveled from 40 to 50. I was at level 50 well before I needed to be. Hell I didn't fight Titan until around level 43, and I didn't do Garuda until, at least, level 49.

But its probably because I enjoy a decent grind, and FFXIV is definitely not a grind heavy MMO compared to many other ones. Well, until you are grinding for poetics and gear, but its still not that bad. The "Ultimate Weapon" quest is though, if you are starting from scratch at this point.