It should look just like the standard res monitor would, maybe with just a little bit of difference in the chunkiness of the scan lines or 'mosaic.' So if anything, the D9200 would probably be considered higher quality (so it's better unless you're a total authenticity freak -- as in you ---smurfette--- about it when 99.9% of human beings can't tell/ignore the difference in a side-by-side comparison) and definitely more versatile (but be sure to use an ArcadeVGA to take full advantage).
If you want to see more in-depth discussion of hands-on experiences, you should do a forum search for D9200.. don't think I've ever heard anyone complain about one of these beauts, though. As for the previous post, Wade should be correct.. the advantage is that you can run Windows and arcade apps at their intended frequency/resolution -- but keep in mind that even the D9200 only goes up to 640x480 max; a std res arcade monitor does 640x200 max and it's at a lower frequency.. but the difference? Probably not something I would care about, unless I planned on playing PC games.
So if you play PC games, too, care how Windows looks, and have the cash to spare, I'd say go D9200. If you're strictly a retro man, just save some $$$ and get a std res.