Thanks for your thoughts, @thepictureman. I'm looking at the options, goodness there are so many choices!
I've done some preliminary research.... I've got a side by side comparison here
. I'd love to know if anyone else uses any of these. There is definitely a savings going with a non Nikon lens, but we're still talking a significant investment. I need to know it's worth it.
Nikon AF-S 12-24mm f/4.0 G IF-ED DX Nikkor Wide Angle Zoom
Sigma AF 10-20mm f/4-5.6 EX DC HSM Wide Angle Zoom
Sigma AF 8-16mm f/4-5.6 DC HSM
Tokina AT-X Pro 11-16mm f/2.8 DX
Tamron SP AF 10-24mm F/3.5-4.5 Di II