I really hate groups that are "Plug in your mic or we kick!" Not everyone CAN talk >_> that's discrimination! :<
I know my job, i can do my job well. I shoot things in the face, i run and go get objectives. It's not rocket science. if i'm not an infiltrator, i'm an adept. i'm very good at making things explode. or priming them TO explode, i'm rather flexible like that. and i'll usually go out of my way to detonate just to see if people catch on. or...i'm an engineer and i'm still shooting things in the face with a rifle. just now i'm throwing energy drain/overload/incinerate in with my bullets along with decoy/combat drone/geth turret.
Communication does not equal a successful gold run, it can hinder just as much if you suck, regardless of how well you communicate. Couple of people i run with use mics, we talk between matches because i can message them and such. during the match..they rarely talk about the enemies we're facing other than making a comment such as "Stop headshotting everything, we wanna kill too -laughs-" "Nice!" "Behind us!" generally, short and sweet, or...comedic. or telling random 4th person to bunker down so i can go do my objectives without going on a field trip
They mostly talk about school, girls, other games, tell jokes...basically...anything BUT what's going on with our enemies. every time i run with them, regardless of what we face. always a successful run, worst case scenario? partial extraction because of our random 4th doesn't wanna join us at the EZ.
I've had just as many random gold runs with no mic's, people caught on and worked together, full extraction and very few deaths. if we had adepts, people figured out whether they were priming, or detonating quick. if not, they still figured out their job well enough. (Granted i've had way more CRAPPY gold runs, where everyone thinks it's bronze =/)
the only thing that matters is knowing HOW to play your class, and paying attention to what your allies are doing so you can work together. microphones aren't going to save a bad party, could they help? sure, but it's not a for sure thing.