I think that stealth suit, is an armor made for a hucaseal, lvl 200 with her evasion at max. Because her, hucaseal, is the char, with most evasion.
Time ago i did a test with my old character called "valkyria", lvl 150... in forest and caves, the enemies dont hit me when i was stand right there but in the mines, ruins and all other levels with more difficult, they hit me, of course.
Maybe in lvl 200 with the appropiate items, for evasion, it would be effective.