I've been using Vegas Pro 13 64bit for about three years or so. All new media I import to a project has it's resample properties set to "Smart" by default. I've never paid that much attention to it until now.
I watched a YouTube tutorial where the author was changing all his resample properties to "Disabled" so I decided to play around with it a bit. I ran two sets of tests. One with 24p origianl media, and the other with 60p original media. I rendered each project with resample set to Smart, Force and Disabled and compared the results burned to Blu-ray disc and viewed on HD TV.
From what I can see there was a significant improvement when resample was set to "Disabled" particularly where there is some movement in the video. Stepping through the video frame by frame, each frame was sharp with resample set to disabled, whereas with resample set to Smart or Force there was considerable blurring for frames where there was movement.
I also noticed a significant improvement in render times with resample set to Disable. 25% for the 24p media, and 33% for the 60p media.
Vegas Pro Help doesn't have a lot to say about resampling except to change it to Force if slowing a clip down. So I'm just wondering what the purpose of resampling is and whether I'm right that it would be best to disable it in most situations.