In general, everyone should first themselves the motives and purposes of use for the relevant objective questions have priority.
My favorite subjects are moving and in the worst case even I myself have a firm footing. Street photography traveling and playing children my clear objectives are based on the Tele. Also I did not want to frequent the lens must wechslen and of course the weight plays a crucial role, especially when traveling on the road. The lens is intended as a supplement to my "Always top" 24-105 / 4 and my two high-intensity fixed focal length (50 / 1.4 and 85 / 1.8). I forografiere in full format with the Canon 6D.
I had initially bought the Canon 70-300 Non-L, which supplied from the imaging performance for me forth satisfactory results. I was unhappy with the autofocus had to pump more times under unfavorable lighting conditions before he was right. Looking for alternatives was the 70-200 4 and 2.8 on the shortlist. Weight and the larger focal range were entscheident for me, the choice thus fell on the 70-300L.
The 70-300 L then has accompanied me along with the 24-105 in autumn 2013 several weeks of India-Nepal travel. Of the nearly 1,600 images, about half were taken with the 70-300 L. In combination, the two lenses complement each other perfectly, especially because of the slightly overlapping focal length range. Whether snapshots short unsheathed the camera from a moving bus or walking out on the street - the autofocus of 70-300L is fast, almost silent and very accurately. The light intensity was sufficient for my purposes and in conjunction with my camera at any time is a problem for autofocus. Shaky or blurry images, there was little and when was the fault not to seek the lens but with me or the numerous potholes.
In the imaging performance I could (home in advance with tripod tested) compared to the non-L at least make no significant differences in the center. Only the border areas came to me at the L-variant before sharper. This impression is subjective and comes from a small number of comparative test photos from, who should be of "lines" and "pixel" is interested in all the numerous laboratory tests on the Internet.
I am very happy with the results achieved, the 70-300 L is a fantastic addition to 24-105L and will accompany me on many trips.
PS: Recently I have me a Kenko dazugeholt 1.4 teleconverter, this is compatible with the 70-300 L as opposed to the original Canon. As the combination suggests in practice I'll try yet - China / Tibet is high on the list of the next destinations.