The Canon 300 f/2.8 is my favorite tele lens, and together with Canon 180 Macro, Canon 24-105 and Sigma 8-16, it constitutes my four lenses lineup. On the 7D, it is the equivalent of a 480mm f/2.8, and with the 2x TC I can even get 960mm equivalent: pretty good for most wildlife. Thanks to its relatively small size and light weight it is a great travel lens, and it is easily hand holdable. As you can imagine, when Canon has announced the new version of the 300 f/2.8 I have immediately been very interested to see the improvements made to this already great lens!
 
Specifications (compared with the previous 300 f/2.8)