Been running Ridorana Lighthouse the whole week and...

[Chyro]

Eh. It's true that mechanics are easier on a class you're used to play on.
I haven't played on my summoner in some time, and mainly levled it in stormblood by levling scholar cause shorter queues.
At first when getting used to it again, I have to pay a lot more attention to what I'm casting and which cooldowns are up.
More attention on what skills to use -> less attention on the mechanics and movement. It's harder to keep track of two things at once.
On Whitemage on the other hand, I'm so familiar with it that I can cast the skills blindly without ever looking at my hotkey bar and can fully focus on the mechanics.
So yeah, I do agree with Ryusei that mechanics are easier when comfortable with your class.

@Cidel: Off-topic, but what game is the picture in your Signature from? Looks fun ^^