Originally posted by ElJamoquio Sincere and friendly question - why do you (seem to) compare the Pentax/Tamron lens to the Nikon lens, rather than the Tamron lens in Nikon mount?
I think the question is how much difference there is between the Tamron version and the Pentax version of the lens. With the 14-70, it sounds like it is supposed to use Pentax coatings and may have some adjustment of optics.
Either way, this lens fills a gap in the line up for a reasonable price and I doubt the Tamron will be released, at least in initially in a K mount. If you are buying a k mount camera rather than an f mount camera, you probably will have the option of this lens and maybe a Sigma ultra wide (assuming they make one in the k mount).
I, personally, am interested in k mount cameras specifically because I can use lenses like my DA 40 limited and FA limiteds without an adapter. I still will need a wide-ish angle lens and having options that won't break the bank will be nice (I am not really in the market for a Nikon 14-24 f2.8, as stellar as it might be).