I was doing stealth get gambit reps today; my partner was mastered so I only had to do 7 reps instead of 14. I did 4 of them hiding the usual way, and 3 using vanish to cut down on the RT. He never saw e hide when I hid normally, but spotted me 2 times out of 3 whan I used vanish.
I have noticed that critters who don't ordinarily spot me hide normally occasionally see me when I use vanish. I am 74 trains, 2.5x in S&H and have all 3 ranks of vanish as well as 5 of shadow mastery. Is there something inherently less effective about using vanish to hide rather than hiding normally?