Using any of the photomerge techniques, IMHO, offers a much superior image.
Except photomerging takes times, and if you are including anything in the scene that moves (wildlife, water, etc), its a big pain to deal with. I'd rather know exactly what my image is going to look like than hope I nailed my photo merges later. Plus, there are some things you can do with the distortion that photo merging can't really match.
The only way I'd agree with you is if we were talking a T/S lens and using it to do the photomerges. But, that's $2k+ I don't have.
my images just looked sharper with the canon, and with landscape shots its much more noticeable.
Weird, I didn't see any difference. I preferred the Canon's autofocus, as I find the Tokina to be slow, but, it's rare that I'm actually using AF in my landscape scenes.
I thought the Tokina had an easier distortion to correct, while the Canon flared less. Both were sharp and great, can't go wrong with either