I hate it with a passion.
My problem with alignment usually occurs when there is complexity in the game. I don't see how to design N/PCs that are one alignment except for X in the system. I don't think there would be a problem except for the various detect spells. If it wasn't for those, I don't think people would care....as an example of what I get annoyed with...
take a Roman centurion who is LG at home in Rome, but rapes, kills, and pillages the Gauls. I can probably leave the Lawful alone...but the good would have to become neutral at best.
Lets flip it...a barbarian Gual who is CG at home, but rapes, kills, and pillages the Romans...I can probably leave the Chaotic alone, but the good would have to become neutral leaving CN the most hated alignment in the system...
I feel like I should have the N/PC's alignment change depending on their current 'allegiance'....LG/CG in their village and LE/CE in war...which seems silly to me to have to do that...
I'd rather have an allegiances type system, but I frequently do not run them that way because my players would revolt.