BiS gear, is it THAT important?

[TempestZane]

For BLM that difference is about 5 dps, making it a 1-2% difference between the combinations of ilvl 90 items you can use. However, make sure you are Always at, or slightly above the accuracy cap! That's where the real damage differences are.

So honestly, unless you really want to perfect your class up to the last 0.xx amount of dps, just make sure your combination of ilvl 90 items reaches the accuracy cap (For SMN, also the pet's accuracy cap). After that, most people will spend the myth tomes on other classes, instead of trying to gain 1 additional dps.

[BrandoH]

No offence to the baddies, but if you have to ask why BiS is so important, you're clearly not a good player. So it really doesn't matter what you pick.

I'm a male BRD, my BiS contains mostly Myth pieces, and it's freaking hideous. But if you wanna look good, just make sure your level 90 set hits the acc cap with food, and make up the rest with skill.

[Maelwys]

There is not just one version of BiS. There should be at least 3-4 for you using only ilvl90 Myth and Allagan. What you need to do is figure out which combination you want to use, you have no choice but to plan for one and do your best to acquire it.

The reason behind this is Acc, you don't want to be behind T5 Acc requirement and you don't want to go over it (with food of course) then maximise the secondary stat that fit your own style or the general known rotation. .

That.

As an example: to hit 100% accuracy for Tanks, you'll need 475 for Turns 1-4 and ~482 for Turn 5. The various Tank BIS builds center around keeping that level of Acc whilst maximising some mixture of VIT (for HP), Parry/STR/DEX (for extra block/Parry mitigation) and STR/Crit/Det (For extra DPS and enmity generation).

If you are missing a few pieces of i90, you can certainly fill in with Darklight or Crafted gear or whatever as long as you keep that Acc requirement (vital!) and buff up the other stats as much as possible (sufficient HP to weather AoEs being the only other thing to watch out for in most endgame situations).