From hometheaterhifi.com......
"What Isn't Better About Progressive Players?
Sometimes you see folks commenting on the improved blacks and color saturation of their progressive players. This is a mirage. Progressive players are not supposed to improve black level or color saturation. The reason they may look different is that the standard black level on a progressive player is different from the standard black level on an interlaced player, for technical reasons having to do with conflicting TV standards. And when black levels go down, the saturation of colors on the screen inevitably goes up, because white is being removed from the color. Once you calibrate your display with Avia or Video Essentials, the color, contrast, and black level should look exactly the same with interlaced vs. progressive. The only advantage of a progressive DVD player is in the lack of interlace artifacts. Of course, if your progressive DVD player is a lot better than your old interlaced player, it may look better for a variety of reasons. But it still shouldn?t change your black level or color saturation.
It's important to keep in mind that most DVD players don't conform exactly to the standards for output voltage. And just as louder audio sounds better, brighter players (ones with higher voltage outputs) will tend to look better, with more "punch." Unfortunately, brighter players also crush the white levels on bright scenes, which is bad. So any time you compare two DVD players, whether progressive or not, you should create two memories on your display, one for one player and one for the other. Calibrate each memory separately with a good calibration disc like Avia, Video Essentials, or the Sound & Vision Home Theater Tune-up (but not THX Optimode, because it's not accurate). At this point, you should get identical color, hue, brightness, and contrast, and can concentrate on other aspects of the picture. If your display doesn't have multiple picture memories, then our advice is to ignore color, hue, brightness, and contrast, because it will look the same once the display is calibrated to whichever player you finally choose. The same applies if you are trying to compare the progressive output and the interlaced output of the same player. If the color or brightness changes, that's not unusual, and is a calibration issue. Ignore it, or set up two memories so you can calibrate the differences away."
It sounds like the picture quality would be very hard to determine between two difference players due to variances in output signal. Thus, I would *assume* it shouldnt be a big deal if you use the DVD or HDTV converter, as (again, assuming) by now they should have some pretty solid converters in the DVD players unless you buy from the budget bin.
Hey, gimme a break, this is a learn as we go kinda thing