I would not go so far as to say that 3D hardware support in linux is "excellent". Probably as good as on Mac, true, but far from excellent. Basically if you want high end graphics on Linux you need to use an Nvidia card and their closed drivers. This closes of a section of the linux community right away. Intel and AMD have open source drivers but AMDs are terrible (no power management, buggy) and Intel still does not approach the performance of Nvidia for 3D gaming. The Nvidia drivers are good, but always lag behind their Windows cousins. Things are improving, but "excellent" is not the word I would use.