Susan: Kind of a meta call. Dies to switchblade, knight and d4vd so I wouldn't really rez or play against those matchups. The strength is it can give PPVP Kate a headache with her typical icebreaker suite. Normally she will need a ton of datasuckers (hard to come by versus RP sometimes) to break it or install a very high strength atman which you are okay with if she does that.
Excalibur: I love this card in conjuction with Caprice or Nisei MkII. It's so strong and so rarely broken. Often your scoring remote can be this with another decently taxing ice behind it. Makes you have to generally just win a single psi game or potentially make the remote impossible to get into if you have a counter and they have no AI/parasite solution.
Cortex: 1 card victory condition! But really, that's rare and didn't happen at regionals for me. It's great because it's at the magic 4 str number for a sentry. This means mimic can't break it without a sucker and d4vd can't get pass it either. It either chunks some early cards out of the runner's hand or acts as very cheap and effective ice for the early game. I like it as just a 1 of because it's usefulness is pretty much just early game before the runner can fill up their memory.