Low: foolishly joined a U/U/P game as the Human Engineer. Ended up on Rio vs. Cerberus.
Juggernaut (played by what sounded like a prepubescent boy), Geth Flamer Trooper, and Salarian Infiltrator were all hiding in the box of shame.
I tried my best to engage the enemies outside and got on the mic to encourage them to come out and play but they weren't having any of it so I ended up hanging around the box of shame myself.
The Juggernaut eventually lagged out. The three of us were able to complete the match but it took 35+ minutes.
Neutral, Just The Setup: I decided to stick around when the host left it on Rio but promised not to box of shame it again. I switched to the Vorcha Sentinel (because it would be a shame to waste all those grenades available) and the host switched to Alliance Infiltration Unit with a Cerberus Harrier.
Hey, people use weird setups all the time. I didn't say anything.
High, Best High I've Had In Months: Around Wave 3 and apropos of nothing, the guy playing the AIU w/ Harrier opines, "People ask me why I put the Harrier on this character. You know why? Because she's Edi, and Edi was part of Cerberus, so she gets a damage bonus with Cerberus weapons, and the Harrier has 'Cerberus' right in its name."

I asked him so many questions after this.
Where did he learn that 'Edi' gets bonuses with Cerberus weapons?
Does she still get the bonus even though she ended up joining Shepard?
Is the AIU actually 'Edi' or just another robot that looks like Edi?
Does the (snicker) Cerberus weapon bonus work with, say, the Mattock or the Talon?
His answers were:
I figured it out on my own.
Yes.
What are you talking about?
No.
So there you have it, AIU advice that must surely be 100% true.
Also the guy had a glorious Staten Island accent so I got to listen to his version of English for another 25 minutes.