300mm f4 or not

I am shooting with a 20D and have a 10-22, 24-105, 100-400, 50mm,65mm. Do you think the 300mm is too redundant with the 100-400 or will the 400 f5.6 serve me better if I was going to add a long prime.

I really like the 300mm IS. I bought a junk one from someone for $1000 and sent it in and I am really missing it. I was going to buy a 100-400 L lens but decided not too at all and I am happy I didnt. I really love how sharp it is and the macro it is able to do.

Talking about Redundant wouldn't a 400 f5.6 be absolutely redundent? After all you do have that covered.

My idea would be, buy a 300mm IS prime (brand new!worth the extra $200) and also get a 1.4 TC that will make it 420mm f5.6. Try that out and after awhile you'll probably find yourself selling the 100-400 and buying just a 70-200 version to fill in the gap.

It would depend upon what you want to shoot with it. If you're looking to do wildlife, you already have one of the best the 100-400. But if you want more reach (birds) and faster AF, go for the 400 f/5.6. Some folks do have both though, or actually all three of them 300, 400, and the 100-400.

I've never had the 400/5.6, but I have had the 300/4 IS. It's advantages are that it's a bit sharper wide-open than the 100-400 zoom, and it has good close-focus distance. It's not a true macro, but it is useful for insect/butterfly/flowe​r photography, especially with a teleconverter. The IS is, of course, a desireable feature with the longer lenses.