The Riot is good for strong headwind shots, spike hyzers, and any shot you want to make sure the disc hyzers out for you. The Halo was good for mild headwind shots. I would tend to get a nice helix out of it with a mild headwind. I also used it for dogleg left holes, because it would hyzer out pretty good near the end of it's flight.
Just remember to grip the Riot a tad more than you tend to do. That's they way it was designed. There thought was, you lost speed if the disc had to "rip" out of your hand. The Riot replaced my Teerex for awhile, but it was so hard to find (because of the clear plastic). I went back to my Teerex, but since I've gotten a better understanding of throwing in the wind. I don't even use my Teerex unless it's uber windy.
Have you had a chance to try them all out yet? Let me know how you like them. Also, if you want to try or plan on trying other discs. Let me know. Chances are I have them lol! So no reason to buy stuff if you don't need to.
One thing I should add about the Riot or any of Lat's disc that have a rounded rim. Work is, they were disgned to pull out of your hand, not "rip". So you are suppose to have a tighter grip on the disc. I didn't notice much of a difference, but I didn't throw it that much.
I'm not saying $50 isn't bad, but if he's willing to take less or even do a trade. Why not? Now if it's a "Gummy" plastic. I'd take it. You can tell "Gummy" plastic, by just the way it sounds. The plastic is very flexable and has more grip. Also, the late runs were pretty close to todays plastic. There was a short run of CE only in name, but soon after it was named "Pro-Line"(Good plastic as well). But there was to much confusion with their "Pro" plastic (the kind we know today). So they then changed it to just Chapion plastic (also the kind we know today). I always stayed away from the late runs if they were not "gummy" plastic, because it just seemd like I was paying more for a cool logo.
There is an SE (Special Edition)Valk on ebay for 32.99. It's a 171g and it's white. SE plastic is nice. It's kind of like a softer Star plastic. I have a few for throwing and collecting. It's a good price for that type of disc. Also $50 isn't to bad for that other disc you had up, but I'd come back with $40 and go from there.
I chose the Valk over the current Beast because of the plastic. I just love the feel and the flight of the CE (Champion Edition) Valk. Plus the newest mold of the Beast is pretty much the same as a Valk. I think the fade and turn are the same. I was using the "old mold" Beast with my Valk, but then I found a Night shiift (diff molding technique done by Innova) Orc and I just love the plastic. See the old mold Beast was more stable than the Valk., so I use to carry both.
Ya, you'll love the Vision. It's a great disc and one of my favorites. If you haven't tried it in Gold Line, you might want to try it. The GL plastic tends to be less stable than the Opto. One of my favorite drivers is the Valkyrie. It's one that I've had since the day I started, although I moved up in plastic. It's a great disc. Two others to look at are the Beast and Sidewinder. I still carry a Sidewinder, but dropped the Beast (to close to the Valk.