Started up a MP session with a buddy, using IP to connect. I'm getting severe stutter right from the start of a mission, as soon as I provide any input to the ship (targeting, rolling, pitch and yaw, weapons recharge). My friend reports everything normal, smooth as can be.

My single player game plays just fine. Anyone know what's going on or what I can check to try and resolve this?

Thank you, turned it to "no". Will test soon and report back!

I'm guessing your buddy is hosting the session, that's why everything is ok for him.
If you're still having problems, you can try to Host the session and check if your friend has stutter.
Also, do a "ping" and "tracert" from cmd towards the IP address of your friend (he may need to disable the firewall in order for this to work). Post the outputs here if you can.

L.E: Actually, for the ping command use "ping -t -n 100 -l 1472 -f <IP Address of Friend>"