<p>I just got mine a week and a half ago. I don't have enough experience with different lenses to have much to really compare it against. (My total experience with lenses: the 18-105mm kit lens, a MF 50mm I use for macro, and an old 70-300mm).<br>
First impressions using it on a D90:<br>
- this lens is significantly heavier than my previous lenses, it's a little too heavy for me to handhold and I need a monopod. On the other hand, it's light enough that carrying it around in a backpack isn't too difficult.<br>
-the autofocus uses up battery power faster than my other lenses, but a backup battery solves that problem and would only be needed if you were planning to be gone all day.<br>
-given the right conditions it can be quite sharp, even if the subject is in motion. The heron pictures in my portfolio were all shot with the Tamron on a monopod, as was the sparrow. I haven't really tested it in truly dim lighting yet.<br>
If you have any questions I will try to answer them.</p>