I meant to add my spec, then forgot... though it seems a vast array of different specs has them.
i5 2500K @4.3 - Gigabyte Z68A D3-B3 mobo - 8GB 1600mhz RAM - Radeon HD6950 2GB - X-Fi Extreme Gamer - 2 x 1TB Seagate HDD's
Running @ 1680x1050 with 2xAA - injFX d3d9.dll - and quite a few texture replacers, though I tend to stick to the 'lite' or lower res version, rather than some of the crazy HD versions, so my system is not being pushed very hard...
The stutters I'm getting now were not present pre-patch, though I did get the 64hz tick/stutter... these are different and more persistant, though some places are worse than others.
