How do those of you hiking with the 500 handle it?
We're all different but I hand hold this 500mm IS II, 1.4 extender, 5D Mark III around my neck for about 3 hours with hiking included. I alternate with right hand grabbing by the collar as if I was carrying a baseball bat to offer an example. I sometimes put my my left hand under the hood and hold with right hand at collar or just carry upright with left hand on cone handle and right on camera grip. The tripod and gimbal are in my opinion just unnecessary every second counts with shooting birds. I won't lie, it's a bit cumbersome and sometimes you want that resting option in which this scenario does not offer. I usually carry along a Samsung Note II to track birds and play calls if needed, sometimes binos and it does take some getting used too..somewhat of a juggling act. Ultimately, you just know in the back of your head all the discomforts that this may bring on is reaped afterwards when viewing the end results. It just doesn't disappoint. I've a friend that uses the 300 2.8 and swears by it and its a great lens but I personally graduated from the 400 to the 500 as for smaller targets the 300 is simply a stretch and with birds you typically can't get close enough thus the extra focal range is needed. Hope this helps.