I am a fan of Begrstrom triplepoints. I bought a used Phazer 3 years ago with them already installed on the sled, and I was shocked at how well it handled. The first year with my new Viper, I hated the Tuners, so the second year I bought a set of SLP Mohawks. Scott recommended 9" triple points, shims and ski savers, and my sled now absolutely rails around corners, and there is minimal darting. I haven't had them long enough to say how durable the triple points will be on the Viper, but based upon the Phazer, they are very durable and you will get a lot of mileage out of them.
I am also a fan of the Snowtracker's, and still have them on my wife's Vector LTX. The Snowtracker's bite hard, but are still easy to steer, and there is no darting. I had over 5,000 miles on a set with my Old Vector, and they still had a lot of miles left in them. They are very expensive as an initial investment, but I suspect that on a cents per mile basis they are still an excellent deal.