I am getting the stuttering too, in many games, to varying but noticable degrees, when using Intel QuickSync and recording at 1080p 30fps. I do not get a stutter when recording with the software mode, even at 1080p 30fps. Setting Action's process priority to Below Normal does not fix it. I have a Core i5 2500K and GeForce 560Ti.
The biggest stutter I get is in Sonic & All Stars Racing Transformed so far
Sonic & All Stars Racing Transformed STUTTER
http://www.youtube.com/watch?v=1Us1mSxGoKQ
Sonic & All Stars Racing Transformed SMOOTH - this is what it is supposed to look like, it's much smoother
http://www.youtube.com/watch?v=uNSR3aGwpM4
CounterStrike GO STUTTER
http://www.youtube.com/watch?v=LwYVyxk3BdI
CounterStrike GO SMOOTH
http://www.youtube.com/watch?v=xOzlVeznmzM
Bioshock Infinite STUTTER
http://www.youtube.com/watch?v=esmIirfw-Xo
Bioshock Infinite SMOOTH
http://www.youtube.com/watch?v=DlzFTxF5Eco
Is QuickSync just not fast enough?