K is definately harder to hide in my opinion. Sitting there staring into nothing makes it quite obvious your messed up on something. I find that I can hide it when i'm rolling, depending on how much I take. 1 pill is very easy for me to conceal, but more than that I just look like i'm slightly retarded with my mouth hanging open. I'd do E, but not in large amounts if you want to conceal being messed up...