Attaching a small, filed-smooth fragment of CD (use those free AOL ones) using loctite works much better (and is less likely to fail at some future point) than simply superglueing the pin itself in my experience

No longer looking - got a lovely one from Matt!

Erm.. in haste I hadn't read the original link, and hence hadn't discovered that it contains precisely the video I linked Still - it does add something new in that people can view the video directly rather than clicking through a site which has merely reposted it

The issue is nicely summarised by this Youtube video:

http://www.youtube.com/watch?v=FL7yD-0pqZg

(warning: profanity)

True, but some people do base their choice of camera brand on what Famous Photographer X uses (most of these people currently use Canikon). More famous Pentax users could help attract such people, and thus through economies of scale result in cheaper lenses/cameras for the rest of us!

If anything the Tamron actually has the edge over the Pentax wide open - the Pentax then has a similarly small advantage stopped down.

They could, however, have recalled all of them or (alternatively) announced a warranty extension only for SDM problems (like Microsoft did with the Xbox 360 RROD), which would have reassured potential purchasers while probably costing a lot less than recalling every 16-50 and 50-135 ever sold.

There are actually two families of older 18-55. The original one (from the K10D and older) has lower resolution than the current lens. The kit lens from the K20D (18-55 AL II) and newer are all optically identical to the WR version.

But that's just it John - they've announced a recall i.e. Sigma will pay for the cost of fixing the flaw, not the customer. If Pentax had announced a recall of SDM lenses (rather than pretending the problem doesn't exist, as they have with the 16-50 and 50-135) then your point would stand, but they haven't.

Advantages of A-series:
*Aperture controlled on camera (dials!) rather than the aperture ring
*The viewfinder is always bright for easier manual focusing (e.g. on an M 50 1.7 if you stop down to f5.6 the viewfinder will get darker, on an A 50 1.7 it won't)
*Supports auto P-TTL flash (ie you set the aperture and shutter speed you want, the camera works out how much flash power to use for proper exposure) rather than having to set the power manually (on a flashgun) or not use flash at all (the built-in flash, which doesn't have manual power settings)