I don’t normally cover game updates, but this one is important enough to make an exception for. A part of the current Friends beta is an update to the Source engine aimed at the longstanding stuttering issue. And what do you know? It works. With
mat_forcemanagedtextureintohardware enabled in the console, the only noticeable stutters on my system are from autosaves.
To see for yourself, add
-beta steam3friends -clientbeta steam3friends to your Steam shortcut, as described here.