I recently ran into sloppy performance while editing footage shot in 24pStandard. The footage played back terrible in the preview window in Vegas. Granted I was using the default NTSC 29.97 template but why should that matter? ....Isn't 24pStandard still 29.97, I thought it's only 24pAdvanced that needs to be run with the 24p Template in Vegas to handle the advanced pull-down.

Thus so far I always though of it like this:
-24p Standard for the cinematic "look"
-24p Advanced for true 24p using 2-3-3-2 pulldown

????

Describe "sloppy" and "terrible" in more detail. 24p standard on a 29.97 timeline can introduce problems if you edit on judder frames (where one 24p frame is split across 2 frames).

Sloppy as in only reaching 9fps in the preview window.

Probably due to edits on judder frames which require Vegas to render. The 24p standard template should resolve that.

It was unedited source footage.

Not sure why - I've not seen that problem.