They changed the course last year, way harder again as the old long hill hits you straight away and has a much worse surface to roundwood.
They removed the avoca git of a climb with a really steep but short road out of the valley, which is much better.
But right at the end you have windgates (aka most of bray head) and the big drag out of enniskerry, with 180km plus in the legs it's hard.
The worst I did on the 200 was with 50km commuting spins, the best with 125 commuting spins. Get the miles in and 65% effort going around and you'll be right.