We haven't tried it though we do use a lot of the scenarios from the Ash Wastes. The downside of the Ash Waste rules IMHO was that the vehicle movement was too predictable (whereas in Gorkamorka it's much more erratic) and I also don't like the focus on the 40k universe much (mostly in the weapons but also in the vehicles).
However, I have considered trying it out someday to see how it plays compared to our own hybrid, and maybe the SF feel is a nice change (that is, if the rest of the group wants to play as well). For now though we'll stick to our High Octane (our hybrid) campaign and smooth out our rules
