I don't think the Star Valk will fade any more than a Champ Valk.
The Viking to me was a dud. I thought it flew exactly as stable as a Valk with less glide, and I just couldn't figure out why anyone would want that disc. It turns out that the top they were using was defective, and the new Vikings (made in the last year) are as advertised...A more stable Valk. I guess the warning is that there are old Vikings still floating around, and they suck. I'm not sure how you tell them apart, either.
As far as other discs go, I'm not sure. Both the XS and Wildcat are good Valk replacements from Discraft, but probably neither would give you the fade you are looking for.
Maybe an Millennium Orion LF. An OLF in either Q or S is a really good moderately overstable driver that will give you that fade. I'm sure there are others as well. The Starfire might be another option, but I find it to be a bit more overstable than I'm looking for. The Orc might also be in that general category. I know people who swear by the Discraft Avenger, but I didn't like it into the wind. That probably was operator error, however. I also know some hardcore Gateway guys who use the Blurr for that type of shot, but the Blurr has a huge wing compared to the other discs I mentioned, so it might be apples and oranges.