Ah yes another lens Q

[Clm]

I have been looking at lenses for my Sony Alpha. I was hoping for input from others on these 3.
a Sony "g" series Sony SAL-70300G 70-300mm f/4.5-5.6G SSM Autofocus SAL70300G B&H
a lower quality Sony lens?? Sony SAL-75300 AF D 75-300mm f/4.5-5.6 Autofocus Lens SAL-75300
a Tamron lens Tamron SP 70-300mm f/4-5.6 Di USD Telephoto Zoom AFA005S700 B&H
I read the reviews, saw the little differences in all of them. the prices are all over the map. On the second Sony lens, the avg rating was 4.5 stars, but some complained of it not being good in low light.
The 'g' series, a comment was made about the lens being faster and sharper than the other sony lens. So in the middle of the road is the new Tamron lens. I know they dont have it yet, but I dont have to have it right now either. I know a lot of you are familiar with Tamron, so thats why I was asking about that lens.
Any input would be appreciated. Thank you in advance.

 

[o hey tyler]

As you can see, the two Sony lenses you listed have the same aperture over the focal length range. They will perform relatively similar in low light.

 

[Rosshole]

I think that by "faster" they mean that it has an internal focus motor that the other sony does not have.