Compare Tamron 18-250 with Canon 70-300IS. Users please.

I'd like to hear from users of either of these lenses(and especially if used both), as

to the pros and cons of each as compared to the other. I read(somewhere) that

the Tamron is surprisingly decent from 18-100mm, but then what? I currently own

a 70-300IS USM lens, but could give up it's extra 50mm at the long end for 52mm

(of the Tamron's) at the short end, but only if the Tammy could deliver equal IQ(as

the Canon) at 250mm. Your remarks?

I own the Tamron 18-250MM. It was my walk around lens and I loved the results.

I'm a fan of zoom lenses.

When Tamron came out with the 28 - 300MM with VC/IS I jumped on it. Both

lenses deliver razor sharp images and are excellent. The 28-300 MM Tamron is an

excellent light in weight lens. My only beef would be its tendency to "drift." It would

be nice if one could "tighten" the lens so it doesn't drift. It is my walk around lens

now.

I believe in the Canon L/IS series of lenses. They are excellent and that will be my

next move on the long end.

I have the Canon 100-400 MM Telephoto. It is a lens that you have to learn how to

use. It does take practice in knowing the lens and the capabilities of the body to

which it is attached. When the 100-400 MM is on it is razor sharp.

I think that the low end Canon lenses are a poor buy. There top end is hard to beat.

I have both essentially. Meaning that I have the 18-250 which I like a lot as a walkaround, and the 75-300 IS (not the 70-300). I have and use L

series whenever I have something of importance that I can plan for in advance. I find the IS essential, but only over 100. Below that, I'm sure

its valuable, but I'm not sure how much. What is valuable I think is the ability to drop below 28mm with a crop camera, and for walkaround I find myself doing that a lot. What I absolutely want to avoid is changing lenses in the field unless totally unavoidable. Then I'll go back to the clean room (my car) to do it. I've had just too many instances where some junk got in there during the change and I didn't see it until later.

Short answer: Tamron is very good, but no IS. I would like that above 100, but I'm not willing to give up the 18-28 to get it--especially when I've got other lenses.