The question: Is there a PPro only (PPro/Encore) workflow that will result in DVD images that don't look soft on a Big Screen HDTV?
The answer: No
Whether from HDV or DV sources, my experience with PPro/Encore workflows is that the resulting DVD looks just fine on a 24" CRT TV, because the display is 480i and the DVD is 480i.
When those same pixels are spread out on a 720p, or 1080p 50" HDTV, they will get very thinned out and the image will look soft.
I there anything that can be done to produce better DVD images that doesn't require a PhD and $200,000?
The few lessons I've learned producing video content to be distributed on DVD is that the final DVD image quality, no matter if you start with HDV or DV, is not due so much to "the one big thing that really, really works great". It is the summation of many small things throughout the production chain- starting with acquisition and ending with the type of TV (480i CRT, 1080p HDTV, etc.) the viewer is using, and now, even the type of DVD player.
1) Acquisition: a good 3 chip camera with a quality lens, good lighting that allows f6-f8 exposure, and staying on sharp focus is important. Always- garbage in, garbage out.
2) For HDV, editing in a robust, lightly compressed intermediate codec (like Cineform CFHD 1080i.avi) will help prevent generational image degrades as you add filters, color correction, effects, titling, renders, re-renders, etc.
3) Determine the best transition file format for getting from the HD on your Premiere timeline to m2v DVD format. The best I have found to date is to export my CFHD 1080i edited timeline to Cineform CFDV 480p (Cineform performs the deinterlace during export), or Cineform CFDV 480i (Cineform will reverse the field order to "lower first" during the export) if you need to distribute an interlaced DVD .
4) Transcoding from .avi to .m2v. Generally best results with 2 pass VBR 6 (8max)mbs. Transcoding software is not generic. Some are much better than others. The really good ones are not free. I have used Procoder for years, but there are a few other excellent ones. It is generally rated as one of the best and has an comprehensive bank of filters for fine tuning and tweaking the final DVD image. I always use Gamma Adjustment, Color Correction, and Sharpen filters. This is not the same as applying similar filters to the clips in your timeline. The Procoder image adjustments are made directly to your m2v file as it's being transcoded.
5) Author and burn the DVD- not much is special about this part.
6) Viewing Devices and DVD Players: The current problem is that most people are now viewing on 40"-60" 720pix, or even 1080pix HDTV. Those pixels from your DVD are getting spread pretty thin and the image looks very soft. I have found that an interlaced workflow produces a softer image on these displays than progressive. A progressive workflow (I make the conversion when I export the CFHD 1080i PPro timeline to CFDV 480p movie.avi)looks significantly better- in fact, using this particular workflow (including the Procoder image adjustments), it looks quite good. To the average viewer, it looks like any standard def signal they are used to seeing on their HDTV. I am also satisfied that it looks better than my DV originated programs.
Something New: The Sony "upscaling" HDMI DVD player ($80 at Costco) will make the DVD images look actually terrific- on a par with just about anybody's programming. It attempts to upscale a 480pix DVD image to match the 720 or 1080pix display with amazing success. This may be the future for those of us who use software encoding.
That's about everything I know about this topic for now.