I have to wonder about the physics = massive lag on lower end machines given how Valve had full physics in HL2 and the Portal games way back when and Nintendo managed to get full physics on everything running on a Wii U. Assuming it's handled reasonably - that is things that don't affect something being rendered don't get physics computed for them, a GPU should be able to handle that for minimal cost, right? Plus they increased the minimum spec for the graphics update which really should reduce the impact further.

All that said, I'm the first to admit I'm not an expert on the matter, if I'm wrong then I'm wrong.