Oooh, I was looking at the Nikon 12-24mm with adapter.... Could you expand on why you did not like the adapter please? Assume you got the 16:9 website one?
Yep, it was the 1st generation 16:9 adapter. I bought the adapter & eventually rented a 14-24 for a couple weeks with every intention of ending up buying one. Well, first off, the 14-24 is indeed a rocking lens. Sharp throughout its range and into its corners, contrasty, built well, etc. Highly recommended for the right person. For me, the fact that at that time (it may be different now, I haven't kept up with the Canon to Nikon adapter evolution), you had to pretty much guesstimate what aperture you were using (except wide open and maybe f/8 and fully stopped down) was bothersome. I also found I unexpectedly missed the ability to AF (it was going to be an all purpose lens, not just a landscape or architecture lens and I kinda suck at fast manual AF). In the end I decided that for the amount of times I really need or want really wide, I could make do with the Sigma 12-24 Mk I I had at the time and hope they would soon make an improved version, which they did. Given the cost and slight inconvenience of the 14-24 plus adapter combo, I just couldn't justify the purchase.
Now, my 24 TS-E MK II on the other hand is the best lens I've ever used and I'm now saving for a 17 TSE (but that's another story)
Hope that's useful.