Hm, no you can´t? - perhaps I cheated and used GI instead?
Besides visualization intentionally looking abstract my renderings are definitely comparable to a GI-version - because I do compare them.
I often see renderings where GI obviously is used but doesn’t enhance realism/ credibility. Or where GI is used but for no reason, meaning: it easily could have been replaced by just few light sources and some smart shaders - at a fracture of rendertime. For that there are also many examples in your own online-portfolio.
Manual lighting does not require a lot of hacks. If you´re comfortable in understanding real light and have a routined analytic eye (skills you always should have as an artist) you will find some really simple solutions that just look very dedicated. So the same result can be achieved by some really simple and effective steps of manual lighting - especially when it comes to animation at a fracture of time.
The lighting-masters at Pixar use GI as a last extra on a manual light-setup that is already virtous. See http://graphics.pixar.com/library/PointBasedGlobalIlluminationForMovieProduction/paper.pdf for “before/ after”. Now that is using GI responsibly!
But having another Pixar-quote from last years Siggraph in mind (“Rendertimes more than doubled”) that little extra in normal studio-/ freelancer-scales could also be achieved by some smart and elegant workarounds.
Cheers
Marc