me personally..... yes!

cost me less, tokina build over all is better in my opinion and i already owned 20+ 77mm filters and have never had a filter to fit the tamron. 67mm filters are used mostly by pentax and zeiss, but both canon and nikon have the 24-85 that uses that size filters.

is the image quality poorer... doubt it. both the tamron 28-75 XR and tokina 28-70 SV are highly rated lenses. the sigma 28-70(not 24-70 which uses 82mm filters) is also a nice lens, but a few people complained of build quality(none of the owners i know had problems though)

your best bet is to take images with the lens in store and deside from the files you get ;-)

i took my 1D to the store and did just that