Last week end I was experiencing some odd issues with editing midi data in PRV mode, mostly using the scrolling forward and back to edit the velocities of the drums, since the composition requires light drum response. The issue still is somewhat touchy even after X3e, those arrows always have being sort of touchy, sometimes they work great and other times the cursor just runs away.
I never updated since X3c but tried X3d first, but the update halted early in the process, so I quit that, lost the launch icon (maybe corrupted file) Rolled back the computer, then clicked on X3e and all went well during update process. The noticeable good thing was UAD plugins issue of inserting multiple UAD plugs, use to require turning UAD off\on to recover the loss response of those plugs, back to the way they were during X2 last year.
Regardless of the fact that win7 is pretty good, some odd issues prompt up with other devices, such as the extra bells and whistles found on my Querty keyboard decide to work after several pushes like mute, volume....once they respond, then they are snappy.