I've been collecting my highborn force for a while, but I only played a few games with them. I mostly use a range heavy list with some mobility. My Atgm and Nyss are constantly on the move while the mules allow me to keep the distance.
In assasination missions I do fine since I can just kite any heavy melee unit and fight them on my terms, it's the take and hold missions that give me fits. I'm not saying I cant win them, but I don't want to unnecessarily handicap myself.
this is what I run for 25pt games.
Arcane Tempest Gun Mages with officer (Leader and 5 Grunts)
Cylena Raefyll & Nyss Hunters (Cylena and 5 Grunts)
Rhupert Carvolo, Piper of Ord
also I'm thinking of picking up either Damiano or McBain as my second caster.