Good looking image! I used the 11-18mm a bit on my a700 and have to agree with your assessment. Glad to hear the sweet spot is able to keep up with the a77's added resolution. It's definitely a lens I would have been a little worried about based on what I remember of it's corners... As long as you shoot for it, and make sure you have some good leading lines pulling you away from the corners and into the sweet spot, it's manageable. The above example is proof of that...

Back to the image though, I definitely like it. Good crop, good choice of BW to highlight the textures in both the wood details and mood of the sky... I'm sure it'd look great as a full sized print...