Edgar_in_Indy:
Yes, I'm trying to bring a smile into this discussion; there's way too much negativism around. I'm only half-joking here, me buying only OEM lenses doesn't help
I agree that 3rd-party support is important, but I'm not yet ready to conclude that Sigma abandoned Pentax; not when they're continuing to launch new K-mount lenses. It appears that K-mount support is slipping behind Alpha-mount support, which is definitely not good.
Other points are subjective or valid only on certain continents - e.g. around here we usually have a 2 years warranty, and Sigma doesn't have an excellent reliability track record.
I have several DA Limiteds, so this kind of "compromise" works for me
I wouldn't mind new versions with DC motors and WR, though. If I'm not mistaken the 70mm was not HSM so #3 applies to it.
And I think they're actually affordable.
P.S. Let's keep in mind there's the Photokina next month.