Went nuts the other day and am still kicking myself for going nuts like that but... it is fun to use. Dang heavy though.
Oh, that is about the Canon 200-400/f4 +1.4TC and the 1D-X. Won't be primary which will still be the 5D3 + 70-300L that I use on walkabouts.
Only used it a couple of times. These are some of the pics. All taken with the extender engaged @560mm.
1. Light not gone but fading fast. Dark bird against dark was problematic for the shutter speed used 1/2000 but thought that grabbing the light side might look nice.
2. Doing their thing. Nothing can escape from the 1D-X
3. Blame Sharon if you do not like this.