This lens is sharp and light and good to work with through out the day but when it comes to post production
the vignetting is terrible and lends to much more work and time correcting this in photoshop.
The mark one version although bigger and heavier I think is objectively a nicer lens but with it's large hood a bit of a lump to spend the day with. However the large deep hood on the Mk 1 does have it's advantages by keeping rain off the front element.
This Mark 2 has such a small hood the front element is very exposed to the natural elements which makes shooting in light rain tricky. All in all if you want quality use a prime... there is a noticeable difference. But if you want a good workhorse to cover an event and image quality is not a high priority keep your Mark 1 zoom!