Nice lens, especially the 0.31x mag at the 1 m MFD.

I got the 70-300L for it's more compact size for travel. The 100-400 II is longer than the current one, I have no plans to sell the 70-300L. Not sure if I'll buy the 100-400 II...I stopped using mine and recently sold it (I use the 70-300 for travel and family outings, and the 600 II when I need reach). I might be tempted if the 100-400 II takes a 1.4x with only a very minor IQ hit (assuming it takes TCs at all).