I was doing caldera for about 2 hours straight last and with it being the class item as the bonus focus for the day out of all the runs I did getting s rank reward on grandmaster difficulty I think I maybe got three class items in that entire time. It was almost always a gun not even made sure I went in and turned off my attunement so it wouldn't override My regular drop just in case. I'd even tried earlier in the day for like a couple hours to get a class item and I think like the first two runs did drop them and then after that. And then that's not even getting into the whole deal of there is no way the ghost actually is doing its job at giving you the armor type that you get. Especially if you select the powerhouse you practically never get powerhouse. It is definitely not a 50/50 chance as was stated. I noticed if I go with something like skirmisher I tend to get it pretty regularly but powerhouse is definitely weighted to not give you it. And then the tertiary stats have to be weighted too because when you do eventually manage to get the type that you're trying to get it'll almost always have health as the third stat. And that health stop being prioritized is across any armor you get no matter what type and then your rewards of any type of armor tend to the majority of the time always be from one of the health focused armor types like Colossus and brawler and bulwark.