Great bang for you pound. Pretty much flawless AF and VR in Botswana this year and not too heavy or unwieldy.
A constant f5.6 as opposed to the usual f5.6-f6.3 at this range.
Still very good for this focal length. If you're looking at f2.8, or even f4, you'll be looking at spending thousands more.
Was gonna get the Nikon but ended up with Sigma 150-600 lens and can highly recommend it as a cheaper alternative! https://www.jessops.com/p/sigma/150-600mm-f-5-6-3-dg-os-hsm-c-lens-nikon-fit-97482?_td_pid=1&cm_mmc=td-_-affiliate_name-_-advert_id-_-236543