I'ver been a pro photographer for over 30 years. Sigma's 60-600mm lens is a marvel of engineering and I can't recommend it enough. I've used a lot of superzooms in my time but nothing holds a candle to the sharpness and clarity of this lens throughout its range. However, it is large and unwieldy.

For a general "do everything" camera - Sony's RX-10 is also remarkable. It has a built-in 24mm-600mm optic in a small, portable package. This camera can do photo and video with ease. It has a far larger sensor than Panasonic or Nikon's equivalent versions. My complaints with this camera are the poor manual focusing options and the low dynamic range of video which requires careful exposure to not blow out highlights.

I have not used the 28-400 in this article. But I do know that the shortcomings of these wide-to-telephoto lenses (not sharp throughout the range, poor construction) seem to have disappeared.