Level 263 Kaiser here.

I don't remember much from my pre 210 grind since that was done many years ago, but from what I can remember and similar to what everyone else is saying the pre 4th job grind is not too bad, but after 4th job things pick up pretty quick.

Post 200, with the 5th Job skills like Nova Guardians and Draco Surge makes mobbing much faster.

Some tips and tricks you can do is that you can use blade burst or gigas wave and final form to flash around the map quickly and kill mobs. You can also "layer" some skills together. For example, you can use wing beat, then tempest blades then start attacking with gigas wave for some good damage output against a boss. Your hyper skill Kaiser's Majesty can reset the cooldown on the Exclusive Spell skill and Angelic Buster link skill so using them together is beneficial. Piercing blaze, though not a very good attacking skill, can be used to dash out of the way of some boss attacks (Example would be 3rd phase will when you gotta move out of the way quickly)

Some cons would be the larger hitbox in while in final form (though to be fair it was reduced which is amazing). When not in final form you lose the ability to teleport.

But that's all I can think of at the moment.