what about people reporting that its not really 300mm on the long end so not providing much benefit over the 70-200 from canon anyway?
It is an industry standard practice to round the values. Canon do it too.
In theory, the front aperture should be 300/2.8=107mm in size. I just put a tape measure across the unobstructed front element of mine. It's near enough 100mm diameter. Therefore either the focal length is a bit less, and/or the focal ratio is a bit slower. It could be either 300mm f/3, or 280mm f/2.8, or somewhere in between. Regardless, it's still a truck load more than 200mm f/2.8.
Canon 1D, 300D IR, 450D full spectrum, 600D, 5D2, 7D, EF 35/2, 50/1.8, 85/1.8, 135/2+SF, 70-300L, 100-400L
EF-S 15-85, TS-E 24, MP-E 65, Zeiss 50/2 macro, Sigma 150 macro, 120-300/2.8 OS, Samyang 8mm fisheye