Buy it, stop thinking about it and get one.

One of the best lens you can get for an a mount , a99ii is my camera and this lens is tack sharp wide open, use it for landscape and other work, thanks Tamron for Filing the need of A mount users. Its a big lens and heavy if your hauling it around all day long but well worth the asking price.

One Year On, An Honest Review.......

I have had this lens now for slightly over a year before I decided to write this review in order to be honest as I can. Now at this point when I read some of the bad reviews about sharpness, I can only assume that they got a a flawed version as I found my version was at its sharpest from F4 to F13.

With an optical construction of 18 elements in 13 groups, inclusive of XGM (eXpanded Glass Molded Aspherical) element placed at the front group and several LD (Low Dispersion) glass elements in the system, aberrations such as geometrical distortion and lateral color are efficiently compensated for...

Its a great ultrawide with some great features, but one or two cons.

This lens is really great. Its lighter than its competitors, its got stabilization and great image quality. But its not without some cons, whether it changes your mind about buying it, is up to you. But, at f2.8, its soft.

Tamron SP 15-30mm f/2.8 Di VC USD review

It's inexpensive for an f/2.8 lens, and has the added bonus of optical stabilisation...

Constant f/2.8 aperture; Fast; high-torque autofocus; Handles with smooth precision

Some sharpness issues when wide open