>>2912809Bigger reach is a myth, over 300mm you will need a lot more focal length and glass. Think 600mm is a good start.
The 150-450 suffers from the same problems as the Bigma, it being big and heavy although it has sealing.
I am still saying if you want a better dedicated wildlife lens, get the DA* 300 and put on a 1.4x TC though it won't be much bigger reach. Your 24 pickles and the sharpness of the lens will provide plenty of crop power.
See pic related to compare how much difference your money is spent on. (hint: not much)
