Solid Construction: OK, we hear a lot about "plastic" feel and less than rugged construction. I think we will have to get used to this construction method as it will be the norm going forward. This lens has plastic components but has a solid feel to it, in fact although I don't recommend doing it very often, you can easily feel the solid build by holding your rig by this lens, you will be surprised by how solid it is.
Glass: Excellent all the way around, very little or no aberations at all lengths, I found very little or no correction needed in post-processing, and for a DX Lens very clean out to all corners.
Zoom Adjustment: Not too tight, not too loose, and with the short throw, getting from 17-50 is an easy, quick task.
Auto Focus: Fast, Locks in quickly, and extremely quiet on the D300.
Vibration Compensation: In my air to air work, the VC worked excellent, and as we flew later into the evening, the ability to open up the lens, and the need to move out to 35 mm or so, the VC still held it's own very well even against my previous Nikon lens.

Auto Focus Lock: OK here is where I will complain about Tamron's way of doing things. On other AF lenses that I have from Nikon, you can turn the Auto-Focus Ring, while the lens is set to Auto and it freely turns without causing any potential damage to the lens. In the case of the Tamron, you can cause damage to the lens if you turn this by accident. This is the only reason it got 4 Stars on my ratings, because I can see situations where accidents can or will happen.
Although not really a weakness, you need to get used to the way this unit locks in with it's VC. It looks like it does a "shift" in the viewfinder once you have done the half-press on the shutter button. I have not found any mechanical or picture issues with this action, it just took some getting used to.
Lock Button: For those who like it, be sure to disengage it before using the lens.

I wanted to provide some detail about my experiences with this new lens, and it's performance in my day to day photography work. If you had asked me 15 years ago, I would have been very hard pressed to recommend a Tamron Lens, but with some work and time, they have managed to sell me on this product.

For both Serious Amateur and Professional Photographers, you will find the lens fast, extremely sharp from f3.5 on up to f22, with a bit of a fall off at f2.8 in sharpness.. But if you have had a lot of experiance with zoom's you will already know that almost all of them have fall off at the extreme ends of their ranges.

For Portrait and Wedding, this lens gives you the ability to do everything that you want in normal to low light conditions and with flash. Adding the VC feature, you will even find that the flash un-needed and still get flattering and remarkable skin tones.

In my Colorado high country landscape work, this lens offered excellent color rendering across the board. I would say that if you are high enough in the hills or away form city traffic, the rendetion is better if you remove the UV filter. In the City, you will find that it is needed (we have considerable ozone at this altitude, and you will need something to slice through that a bit).

Customer Service

I have never had to contact them, so I have no judgement on this aspect of their business.

Similar Products Used:

Nikon makes excellent products and a mojority of my lenses are theirs but they do come at a price point that in this day of lower available budgets for shoots, I have had to make some adjustments in my purchasing power of equipment for work. For that reason I tried several lenses in this range, and between Nikon, Sigma, and Tamron, Tamron won hands down on this lens.