I have been a very happy user of the original version of this lens, let's call it the 'G1', and it had delivered performance that, for the price, is outstanding.
The only areas I felt lacking was a slight decentering issue that has been present since new and a rather pedestrian focus across the full length. Neither of these were deal-breakers for me; the wedding images I was getting were amazing. But that's not to say that I was not interested when Tamron announced a new version of the lens that appeared to have these areas improved.
This review is more of a comparison between the old and new Tamron lenses, as I don't have a huge amount of experience using much else!
Right away you notice that this is a solid piece of engineering. Tamron have included weather resistance with this lens, and there is a rubberised coating to the all metal construction. This and the choice of all metal compared to the plastic parts of the old lens means that this feels amazing. It feels rugged and practical, although so did the old one to be fair to it.
The zoom ring is rather firm. This does make the lens feel even more solid, but this is slightly on the side of workman-like. There would be no smooth zooming in video with this lens. For my purposes though it's no big deal.
I will come onto the button functions later, but while we're looking at the mechanical design, this is definitely something to highlight. The buttons are a different design and offer MUCH less protection to being knocked and the settings changed! This is a pretty bad flaw in my opinion as if you use a Holdfast Style double-strap where the camera is dangling down, it seems the buttons are in exactly the wrong place. The button on/off orientation does not help either; at least if it got knocked into a 'safer' mode (VC On rather than Off or Auto focus rather than Manual) it would be better. Long story short, I have to check the button position every time I take a shot, otherwise it will generally be in Manual Focus mode which for a wedding in bright sunlight where your can't see the screen would be disaster. I'm considering taping the things in position, and I'm not the only one from my limited discussion on the topic.
The autofocus is lightning fast and it's not always obvious that it moved, it the G2 is one step ahead. This is an area that Tamron engineers have put a lot of love into. This is not a a scientific test, but I'd guess twice as fast from the previous model.
The other area of change on focus is the distance. It's now significantly closer. Less than a metre and this makes it very versatile. I am even not using my macro lens as often as this does a good enough job in some scenarios.
Apart from the position of the sodding things and the likelyhoos of being knocked, they are a lovely design. Very resposive and tactile. You have 3 VC modes now - no idea what they all do, comment if you know by the mode 1 is a belter. Less glitchy than the old model, and I am genuinely able to hold hold down to 1/20. The manual focus and auto focus is on the next switch with the final one being for a focus mode. The latter let's you avoid focusing right into infinity to save time in normal use.
The pictures from this lens are as gorgeous as the old version and then some. Minor issues aside I am a huge fan of this lens. Sharpness is even more impressive and the out of focus areas and more creamy and smooth than an already excellent predecessor.
Whether you're shooting wildlife, portraits or events this is the weapon to have in your arsenal. I use it for more than 60% of my wedding shots, and with a closer focus now available, I'm even not using my macro lens as often. Only word of caution is to get some sticky tape for those pesky buttons.