The demos work fine here using the default gl3 renderer. A bit slowly on my old GTS 450 (nvidia's blob version 334) and perfectly on a GTX 760 (driver 340.24). With -opengl4 the 450 produces a mostly black screen (something weird going on with the shaders, or maybe half a gig of vmem isn't enough?) and the 760 simply crashes. There are also weird differences in scene lighting between the two setups. I'd upgrade the driver on my work box, but it's so damn hot today I doubt I can be arsed...