It depends on your needs. I did purchase the Tamron 15-30, however, and I'm delighted with it. I'm about to review some filter systems for it. The Zeiss does take traditional filters, so that's a plus. I don't think it has much on the Tamron in terms of image quality, though. The Tamron is shockingly good. Here is a wide open shot that I took a couple of weeks ago in NYC: