Tamron 28-75 2.8
Much smaller and lighter than either 24-70, and perfect all around lens. 2.8 all the way, goes up to 75, where I often found myself taking portraits.
Copy I had was quite sharp in the centre, in line with Tamron 24-70, but edges aren't it's thing.
However, for people pictures, great. Also inexpensive, small, travel alternative.
They say focus is slow. I don't agree, but it's loud, which makes it appear slower... Vanity made me upgrade to Tamron 24-70, but I'm not sure I'm getting better pictures now...