I bought Sony Vegas Platinum, and while I have now got used to the basics, I hate the fact that the playback in the preview window is very poor. The picture stutters a lot, and so you can't get a true feeling for what you have edited, especially if there are transitions. I have tried fiddling with the settings but can't get it to play smoothly.
My older, slower Mac Mini and iMovie never had this problem.
If anybody else has this issue, or knows how to fix it I'd be really grateful for the advice!