Originally posted by tokyoso SR works with tamron 70-300 lens, but for best results you want SR off especially on the long end.
??? That's not true at all. Unless you mean when using a tripod, or panning, or macro shooting. But in ordinary shooting, you're definitely always better off with SR on than off.
Quote: I don't really see the justification to pay up more for the pentax lens. Much rather spend that difference on another lens.
Depends on how important the difference in image quality is to you, or the 55-70mm range, or quick shift. But overall, I tend to agree. I prefer smaller & lighter lens, so the DA50-200 makes more sense to me than either the 70-300 or 55-300, but between the latter two, I'd seriously considering taking the 70-300 and spending the difference on another lens. Although the "L" version bundled with the K-x is a good enough deal that I wouldn't hesitate to go that way if so inclined.