Well, "match media properties" gives you a pretty good clue as to what to use to render to.
If it's MPEG2 originally, try highlighting a small (say 20sec area) then try the various MPEG2 templates one at a time (With 'render loop region only ticked) until you get one that doesn't rerender. You'll get a "No recompression required" message in the preview window.
How have you imported them into Vegas?

I don't think SmartRender (the "No recompression required" feature) in MPEG2 was available until Vegas 9 (certainly not for Movie Studio, can't confirm for Pro)

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Tim

I think they started smart render in vegas 7

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Wil

Canon HV30 Filter and lens Comparison http://www.youtube.com/watch?v=pK07VxBnqCM
You tube channel (Vegas Tutorials)
http://www.youtube.com/ChapmanPhotography

Indeed, but it seems not for all formats. Though having searched a bit more in the light of your post it seems there's no concensus on which versions really do support smart rendering for MPEG2.
I can't find anything on the SCS site, so I'll assume the rest is conjecture and gracefully bow out of this discussion

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Tim

Vegas 8 pro definitely supports 'smart render'. Both for SD & HD MPEG2. (Took me a while to work it out for HDV).

Bit harsh, MPEG Video Wizard has it's uses, the cutting tool is excellent and it's rendered mpeg 2 files are superb, far better than Vegas.

Which bit of MPEG Video Wizard is indeed extremely good at re-editing MPEG2 streams without recompression contradicts what you said above? Where's the harshness?

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Tim

Interesting. Which settings are you using in Vegas to compare the two?

Tried this experiment before anyway I imported a music video track from a DVD using DVD decrypter, a vob file.
The file is The Seekers - The Carnival is Over (shot on 35mm colour film).
Without editing or changing anything I imported the vob into Mpeg Video Wizard and rendered, straight through in 30 seconds.
The same again using Vegas 8 Pro I matched the source file up ie. 25fps, lower field first, VBR 9500 and indeed as the file rendereded the 'no recompression required' prompt was displayed.
Took slightly longer but that's no problem.
When I burnt both the finished rendered mpeg 2s onto DVD using Ulead Workshop 2 the Mpeg from Video Wizard looked much better than the mpeg from Vegas.
The Video Wizard video flowed smooth and the colours and definition looked better than the Vegas video.
I am playing the videos back using a Sony CRT 34" TV.
Anyway I going to uninstall sony 8 Pro and have a go with Edius 4.

http://img.villagephotos.com/p/2009-6/1341943/S1.JPG
http://img.villagephotos.com/p/2009-6/1341943/S2.JPG
http://img.villagephotos.com/p/2009-6/1341943/S3.JPG
http://img.villagephotos.com/p/2009-6/1341943/S4.JPG
http://img.villagephotos.com/p/2009-6/1341943/S5.JPG
http://img.villagephotos.com/p/2009-6/1341943/S6.JPG
http://img.villagephotos.com/p/2009-6/1341943/S7.JPG

OK. Well the obvious problem to me is that you've set 9500 as VBR, but set all of the parameters the same. (So, top, average, minimum, bit rate all the same). You should set to 'Constant' for that. If you want to go as high as 9500 - which some older DVD players will have a problem with - I would leave the minimum set at 192,000, the average at say 6000, the upper at 9500. That's actually the default setting in the Mainconcept template.
The different bit rates when set to variable are what give you the definition, and smoothness. If you can get into Video Wizard's settings. you'll probably find it's setup similarly for a variable render. I also use the 2 pass setting for a little bit more quality.
I also have canopus procoder, which I believe is what Edius uses. I wouldn't say it's better quality than Vegas, But it's a durned sight slower!