I am sure that the Inter17 is much easier to sail to that rating and it will be much better balanced with the spin than the 5.2 because it was designed for it. A stock 5.2 would get killed by an I17 most of the time.

The downhaul is easy, I have recently upgraded mine and will take a few pictures tomorrow. It only took me about 20 minutes to get mine rigged for 5:1 and it has really helped me getting the sail shape better.