Yesterday I was perusing the dpreview forum (not a member, but I lurk there on occasion), and I ran across a review of the upcoming 16-35mm GM and 12-24mm G. A couple of really interesting surprises in the review:
1. The author's FE 16-35mm f/4 is sharper in the corners than the 16-35mm GM he was testing. This runs counter to some of what I had read, but wouldn't surprise me.
2. The 12-24mm is impressively sharp with outstanding flare and CA control. I'm on record being doubtful that it will be very good, but the review images suggest it will be quite great (for an extreme wa zoom). That really gives me a lot to think about. The size of both lens is pretty amazing, but especially the 12-24mm when compared to Sigma's 12-24mm or Canon's 11-24mm behemoths.
I know people don't like links, but just in case anyone wants to view what I'm referencing, here is the link to the 12-24mm review (the 16-35 comparison review is easy to find on his site): http://www.alinpopescu.eu …nds-review-lago-maggiore/
The 12-24 looks really good in those images IMO. The Sigma 12-24 was massive and not at all something I'd want to carry around. The Sony looks more manageable. For those extreme focal lengths, I'd prefer a single zoom over multiple primes....those focal lengths are so individually specialized that I find it hard to justify owning multiple primes in those ranges. But I don't do much landscape/cityscape shooting these days (I miss it though) so even the zooms aren't on my radar.