Apart from being able to file your own return on time without having to wait for your partner's details. Or maybe your partner has some undeclared black market economy income (e.g. minding dogs or other small stuff) that if you are the assessed tax payer you need to take responsbility for not declaring. If your partner would be the assessed then happy days.
Separate assessment won't convey any actually tangible benefit in either of these scenarios. And you and your spouse or civil partner will remain exposed to being collectively overtaxed if either of your respective income positions change with little or no warning.
Really? I had thought this thread and my post were discussing Irish taxation assessment rules exclusively. Many thousands of mixed-domicile couples reside within the State and the Revenue's remittance basis rules, which are the point of my post, are the same for all.