I have 2 chars.

One on Moogle (EU), one on Atomos (JP)

To date (Throughout Beta 4 and so far in EA)

Moogle - Always a queue to log in (lowest I seen was 15 in line, highest was 156)
Atomos - Never had to queue, always direct log in.

Moogle - Very laggy, huge numbers of people competing for mobs (yes I know you can "share" but with 6 people hitting on 1 mob, it does not last long enough to get credit)
Atomos - Take your pick of mobs, most I have had to compete with was 1 other JP who was very polite and we shared cures/pulling for 30 mins.

Moogle - Had 3102 error (22hrs), 90000 error (current for 2hrs), "Instance crash", repeated "Lost connection to server" messages.
Atomos - yet to drop connection or be unable to log in.

I do not agree that the JP servers need to be either shut down and/or given to EU/NA players.
But SE truly does need to add at least another 5 servers to the current number of NA/EU list to spread the playerbase around somewhat.