Opinions on Canon EF 400mm f/5.6L USM

I have been thinking about getting a 300/400 t/photo and I am torn between the F4 300L and the F5.6 400L and I would value any opinions here.

Thanks
Chris

the first question is what are you mainly looking to shoot?

Mostly birds and small animals.

I can't comment as to the 300 as I've never used one, but I can tell you the 400 is an excellent lens: very, very sharp and very fast-focussing. It's awesome for wildlife, especially birds in flight.

yea, for birds in flight the 400 is king for sure. I would reccomend the 400 aswell, its an awesome lens for nature.

Thanks folks, my order is in for the 400!

I know I'm a little late to the party, but I thought I'd throw my opinion out anyway since I have both. The 400mm is a great lens for birds if you can get close and have good light (for fast shutter speed.) The 300mm is good if you can get really close - I bought one specifically for use at a backyard feeder and for larger subjects. If I had to choose one for birds, I'd definitely take the 400mm. Sounds like you made the same choice! Warning though, once you get the 400, it doesn't take long to start wanting/needing the 500.