Joint finances here.
AXH, not a good situation, separated mine out just prior to divorcing him.
AH, is working out much better; I have had exactly two overdraft charges in my 51 years on the planet, and my AH doesn't know much about balancing a checkbook, so I balance the budget and let him know how much we have left after the bills, and we mutually decide how it is to be spent.
Of the couples with whom I've spoken about joint checking, most have joint finances. Not many separate them out entirely. There are a few who also have separate accounts in addition to the joint account.
My analysis for my own situation about joint finances: Go with what works, and change what doesn't.