Right.
Firstly i want address the difficulty of DS4. It seems that its not possible survive till the end, unless you have SM or RF+BK buffs. I've spoken to people of HARDCORE guild, and mostly all agree that DS4 should be tuned down. The mobs hit way too hard, even in first spawn. (120-150 with 700 def)
Twice now I've died in DS4 with 5 people party , if DS4 is so hard, that i'd like to know what DS6 is like. I mean cursed dragon hits me for 160 dmg, which is understandable, as that is a boss, but kalima mobs in DS4 ? Anyway, you might want to consider tuning it down a bit (and DS5 swell i suspect)
Blood castle is pretty well tuned, but DS is not.
Secondly, i wanted to ask if feather/crest drop is intended to be as low as it is. People from HARDCORE told me that they've found 1 crest/feather over 4 days with nonstop kill. Others said that they've been afk there with fast kill for 3 days, still no crests or feathers. At this point i think more feathers have dropped from IT , then from Icarus. (don't get me wrong, i know drop should be low for a low exp server, but 5 member party finding 1 feather/crest in 4 days seems a bit too low, especially as 2nd wing mix rate is not 100% guaranteed.)
Anyway, that is my feedback ,and i'd love to hear other peoples opinions / feedback.
Cheers!