I have a lvl 52 SK with +5WIT tats, and I'm not noticing that much of a difference other than casting speed. I heard that WIT tats are the only decent tattoo an SK should get, but mages can still sleep me as often as they normally did, and in C5 WIT won't even govern magic debuffs. Are these the only tattoos worth getting as an SK currently, or should I not even have them?
I used to have +4 WIT on my AW but eventually switched back to the default setup.
From my experience your debuffs are based on your INT in two ways. It refers to your m.att, and then your INT also to see if it lands.
With the changes in C5, there'll be little point beyond casting speed for the +WIT setup, so i'd drop 'em. Maybe experiment with a demon set and some friends to see if your debuffs work better and then go +INT if you like it.