I did purges till lvl 8, there are some elite thralls i got, cormag beastblood figther, and anja the dervish archer. They start with 3500k life +/-, and had good attributes, got some regular thralls too, lian, nordehemian berserk, corvic the blade, mei the blade, got a danlisia too, i not noticed if she is better than the one got in map, she has 1800k life +/- and the same attributes the normal one. Got a lot of t4 bearers too.

One negative aspect of the cage system in my opinion is that there are no crafter thralls and priests, and barkeeper should not be a follower but a station thrall.