High: Playing the Kishock Volus Adept like he's a mini-infiltrator, sneaking around and Stasis headshotting all the small stuff. And getting downed only every few waves - managed one game where I wasn't downed at all, barring a Banshee grab (yes, she can see through the cloak, maybe those glowing orbs gave me away?)
Low: Discovering the Kishock doesn't work so well on the Volus Vanguard 
High: Rediscovering the pleasures of the Batarian Gauntlet on the Volus Vanguard. punching an Atlas in the knee joint seems ridiculous and hilarious at the same time 
Low: Still several hundred waves away from completing all the character challenges.