Thank you, Jerry, glad to hear you like the fall reflected waters in that shot.
I also do not hesitate to use 300 f/2.8 IS MkI + 2xTC MkIII combo as it is relatively light and it yields good IQ as your fine GBH shot illustrates full well.
For a few days now I have been trying to make a closer approach to a young Black cap night heron, however, to no avail. The bird is too far even for 800mm FL as the shot below illustrates.
In many spots the fall colours are now peaking, and the leaves have started to fall off quickly, but the problem is in getting that bird in the right spot.
Handheld 1DX + 400 f/2.8 IS MkII + 2xTC MkIII, about 50% crop.