I don't have this yet, but I haven't had stuttering in Source engine games for a very long time. HL2 is completely smooth for me now, except in a few cases with lots of objects reflecting in water (I have it set to "reflect all") it dips into the 20-30fps range.
The only time I hear stuttering of any kind is when I change resolution or graphics settings and it has to restart the renderer.
So I doubt I'll get any with this game either.
