I will just echo what Kris and Robin wrote.
IQ wise I believe DA35 is great lens, but the main differences are somewhere else:
a) is f2.8 fast enough for you?
b) is FF coverage important to you?
c) is MF important to you?

I used to have DA40 and I loved it. But swapped it for FA43 simply because answer for a was NO and c was YES.

generaly FA &F series lenses don't have great MF feel to them but FAltds seem to be bright exception. They MF rings have great feel and good throw.

BR
Peter

I did try Sigma 100-300. It's stunning lens. Bit on the bigger side but fantasticly build, with great IQ right from f4. It's IF as well which is neat.
On the other side, nearly all owners of the DA*60-250 are very happy with it.
DA55-300 is a very good lens, but I don't think it measures up to the standard of those other two...

having said that, I have only really tried the Sigma

my 2p

As far as I know the FA28-200 is the rebranded version of earlier Tamron design.
I used to have Tamron 28-200 Xr Di (IF).
Not a bad lens. Fairly compact, with adequate IQ and good zoom range. Build was on the lever of kit lenses. AF pretty fast in good light. In lower light the lens struggled. Not just with AF but it's aperture range 3.8 (28mm) to 5.6 (200) didn't allow for much indoor flashless shooting. As well it's only 200 when focused to infinity! Focusing closer you are loosing some focal length since it's IF "megazoom" (though I believe the FA28-200 is the same in this respect).

All in all it wasn't bad lens, but I don't miss it.

Here are some pics with the Tamron on K100D

I would say as long as they will keep screw driven lenses in production (f.e. all ltds FA&DA) they will be keeping screw driver in the body. Once they stop manufacturing those lenses then they probably will abandon the screw in camera too.

my 2p

over on Pentaxforums.com you will find thread full of pics by a lot of folks owning Sigma 10-20 (mostly 1st ver). link
I'm one of them... Have had this lens since winter 2007. And I never thought of swapping it for DA12-24.
10mm is just great! It's hard to make pics with it if you don't know how to deal with the aspects of ultra wide angle photography.
Most of my shots with this lens are at 10mm and very rarely the lens goes over 14mm.
The DA12-24 may be superb lens but at roughly the half price for the 4-5.6 version you can't go wrong with Sigma IMO.

I believe they are indeed

Camera is now SOLD.

Out of those you listed DA40 would be my pick.
I owned one for 2 years. I nly sold it after I bought 43ltd.
Extremely good lens and outstanding value. Don't be fooled. f2.8 is fast enough for 90 per cent of indoor situation and the lens is focusing supefast, and is practically as sharp in the corner as in center even wide open!

BR
Peter

Doesn't the DA* cover FF image circle?
---
and yes, £480 is cheap indeed.
Last one I saw went for £549 in srs in November.

BR
Peter

Thanks John.
I'm not looking at the f1.4 versions in whichever incarnation. It's simply too far out of reach.
But I wouldn't mind getting 1.8/1.9/2.0 version of Pentax 85.
Oh, well. I'll see

BR
Peter