Out of interest, if you live in the US why don't you use Adorama/B&H online? They've always struck me as the "holy grail" of photography stores (in both price and service), even for Pentaxians.

The Tamron is much more widely celebrated, though the Sigma is sufficiently obscure that I don't know what (if anything) is "wrong" with it to make it less hyped than the Tamron. As the previous poster said, don't look back: the Tamron is an extremely good lens (sharper wide open than Pentax's £700 DA* 16-50 according to some reports) and well worth it.

I got mine a week or two ago (SRS have them at about £100 less than they were before) - it is definitely worth the money. I wasn't sure when I ordered it whether I'd done the right thing, but it is a stunning lens.

Ah, must be the US that doesn't have the 35 yet.

If I remember right from buying my K20D, it tends to be a money off voucher for Pentax accessories/lenses (with the discount being between £5 and £20 depending on the value of the item)

They aren't getting the 35 f2.4 until then either if I recall correctly, so not necessarily cause for despair.

Well my Nokia 5800 has a "Carl Zeiss Tessar" lens in it

Apart from the speed, not much. FA lenses generally have PF problems when used on Pentax DSLRs - see e.g. this thread on the other forum for the FA35 - and the FA77 is particularly prone to this. In fact, the purple fringing (along with quickshift and cost) are making me rethink my long-held desire for an FA77, in favour of the DA70.

The one issue which you should be aware of is the differences in focusing between the DA35 Macro and the FA43. Obviously macro lenses can be ponderous if they decide to hunt, but as far as I'm aware the FA Limiteds aren't exactly speed demons either. The difference I want to highlight is in how the focusing range is distributed: the DA35 Macro has only a very slight turn from 2 feet to infinity, so I don't imagine MF would be much fun in non-macro situations. Also (and unusually - uniquely? - for a quickshift lens) the DA35 Macro's focusing ring turns during AF operation, so you need to find something else to hold when AF is on!

As far as hypothetical 'full frame' goes, the DA70 can be used on film cameras without vignetting whereas the DA35 Macro cannot. If full frame digital (or film) concern you then perhaps either the new DA 35 f2.4 or the DA 40 f2.8 would be more suitable: both of these give full-frame coverage.

Do you want your new kit to have a macro capability? If so then I wouldn't rely on the DA 35 Macro - in my (limited*) experience the working distance is simply too short for 1:1 (great for indoor 'closeups' though). If you envisage doing a lot of 1:1 flower shots (etc.) then the DFA 100 should be top of your list.

*pun unintended

If you're thinking about the Voigtlander you'd better be quick: they've gone out of production (in Pentax mount) and are out of stock at the UK dealer. eBay price spikes coming very soon I think.

It still baffles me why Pentax didn't make the 17-70 a WR lens - a "landscape zoom" without WR has to compete with the Sigma 17-70 and the kit lens let alone the various f2.8 options out there.