I'd argue that if you wanted the Sigma f1.8, you'd buy it specifically because want to be using the f1.8!

Agreed... it's great to have the choice. Two very different lens propositions. There's currently a bit of a trend for small DSLRs/CSCs that look a bit like classic camera bodies, and this lens will help create that look and feel on current Pentax bodies.

Maybe they'll release a paired 10x TC (jk)

Shame it's not f1.8 all the way for that matter, a la Sigma 18-35.

Still, it's nice to have a small classic looking zoom. Should be lightning fast auto focus given the short distance from min to infinity on the focusing scale.

Maybe not, but that's what many people seem to want!

'Ahhhh.... wearing a personal catheter is so liberating....'

The larger sensor size does seem to provide a noticeable upgrade in IQ. It is 50% larger! But I agree, I much prefer the look of the original Q... not sure why they felt they needed to change it.

Lack of foam light seals is one reason I always recommend the P30 and it's variants. It's also beautifully simple to use. Plus for some reason it's dirt cheap!

There's something lovely about using primes.

But there's also something damned convenient about a fast AF zoom like the Tamron 17-50/2.8. And you don't lose much (if any) image quality with it compared to most primes.

There is an occasional 'chirk' as the SR moves the sensor. Nothing objectionable. I agree, the K30 system isn't as good, as far as movie SR is concerned. (It's better in all other respects though!)

I know what you mean. It's kind of obvious that the K3 noise performance will not be significantly better than the K5.... the sensor technology hasn't moved on that much. It's also likely that it will not be significantly worse. All of the image samples I have seen seem to confirm this!

Either way, you know it's going to be 'good enough' (and in your case, a step change over the K7!) It also offers a few subtle enhancements over the K5ii to keep it in line with, and in some cases ahead of, the competition. All good.