Road to 70 Buff

[Mhaeric]

That lodestone page with server statuses is always up to date.
https://na.finalfantasyxiv.com/lodestone/worldstatus/

Sargatanas was a preferred world from August 10 to September 8. The change previous to that was all the way back in April 7, so it was standard that whole time.
https://na.finalfantasyxiv.com/lodes...428d0cdf5c44a3
https://na.finalfantasyxiv.com/lodes...0430f5b02303e3
https://na.finalfantasyxiv.com/lodes...9dc1cf57155cd1

They change the preferred/congested server statuses fairly infrequently, so check the news section on the lodestone for posts titled "Regarding Changes in Congested/Preferred Worlds" to see when/if Sargatanas changes back to being preferred. They don't announce these changes ahead of time as far as I know, they just post it on the lodestone news feed when it happens. It's based on population numbers and can be considered the rough equivalent to other games designations of low, medium, or high population servers. The setting that turns on and off character creation is mostly separate from this and is based on current active population, so even if a world is preferred you might not be able to create a character if it is during peak time with lots of people logging in. Congested worlds always have character creation turned off, though.

https://na.finalfantasyxiv.com/lodes...ews/category/1

As for the Road to 70 buff itself, the exp boost is quite nice but it's no longer really needed after the experience changes and modifications to the main story quest they made in 5.3. Even without the road to 70 bonus you will always be higher level than what content the story locks you into anyway. Some people even complained how much experience they were getting. There's other bonuses to creating a character on a preferred world, of course, so their decision may or may not be swayed by that.