No experience with Vikings. They seem to have a good rep. I have seen guys beat on QA1s pretty hard and they seem to hold up fairly well considering.

I like AFCOs. They make nice stuff and many custom shops use their components.

Admittedly, I'm a shock snob, but not everyone needs $4000 (or more) worth of shocks on their car. But it is easy to get outside the window of what a shelf shock can do with the power, suspensions and tires available today.