coverage isn't as good but enclosure is greater making them sweatier.
i have both,the poc padded bit is a good 3rd bigger than the KS, both in length and width. the KS is an inch longer over all. the KS has more side padding than the poc. imo the poc raps around the knee better negating the need for the extra side padding. i agree they're a bit sweatier. found the KS to pinch a little at the back of the knee, where the poc's don't.
had a big otb on a steep rock section at mt. creek. (where the US open is held) front wheel got jammed between two rocks and pole vaulted me into the air landed on one knee in the rocks from a long way up. the poc pads worked great and i was glad i had them on over the KS.
i guess it's like most things, personal preference...