Which lens do you mean... there are two 28-105mm canon lenses:

Link

I would check that site for other lenses you might be thinking about - as they are user reviews it comes with good advice as people have used the lens for a time before posting their review.

*"I need something that can take photos at concerts (dark, close range, indoors), portraits, and out doors general shooting."

*I have the 17-85mm IS USM - and that is a good all round lens.  However - you have just outlined a rather broad range of shooting conditions... The IS is good for indoors shooting, although it isnt the camera moving which you should be worried about there (the IS will deal with that allowing you a slower shutter speed) it is the subject moving (the IS wont help you there - nor will the f4-5.6 aperture). So if you want to get good indoor shots it is either invest in a good flash or use a low aperture lens - the 50mm f1.8 or even f1.4 is good if you can get close to your subject.  Which brings up another problem - distance from subject.  The 17-85mm is good for "general shooting" but unless you are close to your subject you wont get much range (thinking outdoors and concerts here).

I'll close by saying that the 17-85mm is rarely on my camera.  I have the following lenses as my "core" carry all solution: 70-200mm f2.8 (distance work in all kinds of conditions) and a 10-20mm (landscape work and general wide angled fun) with the 50mm f1.8 (portrait work and maybe low light stuff too).  But that is me - i try not to work with a compromise - i change my lenses a lot - maybe you dont like doing that... in which case it will have to be a compromise for the specifications you mentioned.

IMO...

"In every colour, there's the light.
In every stone sleeps a crystal.
Remember the Shaman, when he used to say:
Man is the dream of the Dolphin"

Rich Meadows Photography