On IE9, I get 19-20 Mbps Down and 1.95 Mbps Up. Chrome and Firefox Down usually 20-25% lower than IE9 (around 15-16 mbps down) Up all are 1.90-1.95 mbps.
These are average results, they are very consistent from one test to another (+/- 10%) since I installed a DOCSIS 3.0 Modem. Used to get wide variations with DOCSIS 2.0. On TWC. All 3 browsers are Vanilla, no add-ons or tweaks.