I'm leaving one in the ??? area because I like that level and I can use it to access DW and the surrounding area, the second one I'll place at Onnet because it's the closest to Sards and can work for MoD as well (my two most used PK spots). Not exactly sure where I'll put the third one, I'm thinking inside the castle because of the daily quest. I really can't see myself using any of the other locations very much.