Problem with a 300 prime is so many times you are just to close to the animals to get a good shot. That's why I went with the 70-300L. Worked out really well. Don't get hung up with 600mm shots...there are so many photo ops when you're right on top of the animals. Many times I was shooting at 70-100mm.
Of course there are times when you may want that 600mm reach. 






