Do you mean wethere there is a difference between hard mode and normal mode chests?
or
Using keys as apposed to lockpicks?
or
Maybe if you /kneel before opening that you get better drops?
well, high end chests have the good stuff in NM and only those will count towards treasure hunter. In HM ALL chests are good or even better then high end NM chests. HM chests > NM chests.