Originally posted by Class A (or for some reason needs the focal range of course).
Then you should go for the Tamron 10-24
unless you want pentax brand and paying almost 3 times the price...
+1 with the 11-16 f 2,8 i would jump head first if that lens was available.
And then about the lens lineup and how they are the "same"..Thay are not: barrel design and coatings are not the same and those two things have a consequence in the resulting lens... The other day i read how the 12-24 Tokina was considered only a decent lens by canikonians while pentaxians considered pentax one to be sublime. The poster argued that Pentaxians overrated the lens but i started thinking that maybe coatings and barrel design made some difference here and that explained the difference in appreciation.
Independently of who owns who, what are the plans, etc, as a consumer i would love to see more Tokina K mount lenses out there, competition and choice are always good for us (price wise).