Originally posted by elho_cid WR, silent operation, precise AF, distortion and CA correction in jpg automatical in new bodies, nicer bokeh... there are more differencies.
I just posted a quick reply and mentioned one of the main differences. Yes, since the Tamron uses the in-body screw drive it does tend to sound like an electric drill-driver from time to time but it doesn't really bother me. I must have gotten a good copy because my 17-50 nails the AF everytime. I shoot RAW so distortion and CA isn't that much of an issue. I agree, the DA* does have an excellent bokeh and build better but when I was in the process of deciding which one to go for, I just had a hard time justifying the DA*. Frankly, the SDM issues I've read from owners did scare me.