Yes 0.2 is against drag and lap timers. Think about it, if your GPS is polling 10 times per second that's 0.1 s per data point. Dashware and QStarz software seem to calc crossing the line differently. Most of the time it's pretty close to Natsoft but can be out up to 0.2 across different software packages.
If you want more accuracy you have to be willing to pay $100's more. Just part of the technology really.
And Jimmy, you still have to open both video and GPS files, pick a point on the track and sync them that way. It's a but if guess work to get it right. Think about it, you aren't starting the video and GPS capture at exactly the same time at the track so you have to do it manually on your computer in Dashware.
All just part of learning to deal with the Tech. I can get it down to about 10 minutes of fiddling now, but that's after lots and lots of practice.