So red chest have better loot than grey chests, I get that, but there’s a rumor that some of the red chests are better than others (“dev chests”, with increased odds of containing legendaries and stuff).
As far as I know, there’s one in Tundra Express where you have to suicide to get to it (I mean afterwards, in order to exit), there’s another like that in the vault of the warrior, one or two in Arid nexus, etc. And I noticed that I got a legendary item twice in normal mode after farming the chests in Marcus Munitions Storeroom, so it would seem to be true.
…Or am I wrong? …and all are equal