Warning about the 24-70mm F2.8

There are many people who like this lens as a Tamron and a number of reviews that sing its praises, however there are 2 reviews where IMO they clearly got bad copies, given that the Pentax is a Tamron clone expect that it may be designed in such a way that it requires high tolerances to be maintained to obtain great results meaning there could be a great deal of sample variation.

These 2 reviews report it as rather weak, i suspect if you get a good copy your experiences won't match these reviews entirely

http://www.lenstip.com/340.1-Lens_review-Tamron_SP_24-70_mm_f_2.8_Di_VC_USD.html

http://www.imaging-resource.com/lenses/tamron/24-70mm-f2.8-di-vc-usd-sp-model-a007/review/