I don't think there's much wrong in what Duck is saying, but then I'm not a fan of O'Gara.
He's done some great things with Munster and to a lesser extent Ireland, but he was a player who was only capable of playing one way, and that was to kick the corners and kick the points. He was bloody good at doing that most of the time, and when you add on the fact that he could also keep his cool and slot important last minute dropped goals he's deserving of some praise.
However there were some glaring holes in his game. His tackling was simply shocking as is well publicised, his attacking game was week for the majority of the time and mostly consists of shovelling the ball to the closest player. His main attacking threats came from the boot with some delicate grubbers, and accurate cross-field kicks and up n' unders. He could be liable for some shocking off days as well, mostly in the green shirt, but still...
I also think like duck that he was somewhat lucky to be playing behind a strong Munster pack for most of his career. However he certainly contributed to Munster's success by putting the pack in the right positions of the field to cause damage.
The fact that he's also a bit of a prick off the field just lowers my opinion of him. His behaviour in front of the queen for example was simply shocking, and that's coming from someone who is certainly not a royalist. You wouldn't behave like that in front of any old lady.
Overall I'd put Sexton waaay ahead of O'Gara. Jones was easily better as well.