I used this lens and jotted down some thoughts a couple years ago but did not have much experience with telephoto lenses as a basis of comparison. I now shoot on the 70-200 f/4 and still want to get my thoughts at for this budget option zoom lens.

This Tamron 70-300 is an older lens I borrowed to attempt to snag some shots at the US Open from way up in the stands.  The owner advised me to not shoot on anything over 25omm as detail will be lost.  I did a quick test at 300mm and quality and distortion did seem a little off. I was shooting all night on shutter priority with no stabilization equipment at 1/200 and higher. With a decent amount of handheld shake I noticed in camera I would lock in my frame as best I could with good form and elbows in tight and got good images as far as this shutter speed and lens stabilization went.

The biggest drawback on this lens I saw was in the autofocus in combination with the T3i. I could feel the motor and hear it was very loud.  On my T3i body, I felt like the autofocus was always just a little bit off. I tried the AF on continuous and one-shot and got refocuses on still objects multiple times. Overall I think this is a good budget zoom option but with the lack of detail at full 300mm and is no comparison to a 70-200. I would recommend this though as a travel lens for those with family and children and is only ~$140.

For full specs and to purchase find on Amazon at http://amzn.to/2vmMfj7.