One last time before I give up the Vegas ghost, perhaps I don't have the system setup properly to achieve flawless smooth playback from the timeline of Sony MVC/MTS files. Are there any special handshakes or tricks to accomplish this, or do I have to transcode everything to MOV and move back to FCP where smooth playback is never an issue??

I have to use Vegas to process Sony NX3D1 MVC files into separate Left eye / Right eye files and would like to stay and use the stereographic tools in Sony Vegas 10E, but the playback thing is a real deal breaker.

Any suggestions to help this out are appreciated

System: Intel DualCore Quad 2.33 GHz / 8GB Ram / NVidia GeForce 285X Windows 7 Ultimate / Vegas 10E

The reason playback is "never an issue" on the Mac is because you're constantly converting all of your footage into the format they want - a very time consuming (and disk consuming) process and something even Apple is getting away from on the newest version of FCP.

For smooth playback of mts, the most important factor is your CPU. If you look here:
Vegas Pro 11 Coming Soon (http://www.sonycreativesoftware.com/vegaspro11)

Vegas Pro 11 will be out soon and one of the new features is GPU accelerated playback so that may be something you want to look at as well.

NX3D1 60i files on timeline, preview set to half quality, display only the left stream, and
i get 3fps with my 3.3GHz dualcore CPU :(
So what is the minimum CPU for smoothplayback without any FX and gpu acceleration?
(in "preview half" quality)
Now with mediaplayer i can playback with 30% cpu usage in fullhd quality, but Vegas11 use 100% CPU, so editing is impossible. So i need a 10x more powerful cpu for 30fps? Can't be. Why is it soo slow? I know it's AVC (MVC), and Vegas is an editing not a playback program, but i don't see a reason why is it soo slow without any fx?