Cool, I've noticed the 3rd party lens makers are really putting an effort into their products lately. I even got myself the 50 mm Sigma Art 1.4 and boy is that sharp. It's just that although it's a excellent lense, it weirdly doesn't make it as a favourite. The 135 mm Super Carenar 2.8 I mentioned is a lens almost 40 years old and it's still one of most used lenses. :)
I think I need to check out whether there's an affordable Tamron zoom for outdoor and nature photography.
They probably have one. They seem to be a good company. There are still things Nikon and Canon have over them but the price and better warranty and sharpness is hard to be when you're saving $500 or so. Also Lightroom let's you do lens correction which helps a lot in some situations.