Transfers to low populated servers are not worth it
I transferred and made characters on Zalera because of the incentives, mainly the Road to 60 buff. Now that Zalera is no longer a preferred world, less than a month after incentives, we lost the incentives without any warning. That means that any preferred world that you transfer to can have their preferred status removed at any time and you lose those incentives. I have friends who transferred last week and lost the incentives with this patch.
There is no warning, you could lose them once the server is filled enough to Square's liking. That shouldn't be how incentives work, it's a cheap ploy.