My preferred is shiny steel, but I wanted a change so I ordered the Ti. I wanted to like the natural Ti, but I was also having trouble setting up cellular so I returned it within the 14 day period. AT&T has since told me they're having trouble with their system so my Ti was probably not defective. When I returned it the Apple rep talked me into getting the silver Al predicting that S7 will be a redesign and the Al is a good transition AW. IMO, the Al looks better now than the early series, the anodization looks better.
Since I'm planning that the Al will be a one year AW for me, I've accepted that the Ion glass will be scratched up. I had an Al AW in the past and after one year there were a few fine hairline scratches. It seems inevitable with the Ion glass. The Ion glass is more clear though, supposedly because the Ion glass doesn't reflect as much as the sapphire.