trade 24-70 for 24 105 IS?

I recently shot a wedding and used my brother's 24-70 on my 20D—up until then, my next lens was going to be the 24-105 IS. The keeper rate with this lens was outstanding! Fast, accurate, low-light focus made the difference. But it always comes back to the application—as a walk-around, the extra reach would be nice—and then there's the IS. The ability to shoot at 1/15th of a second hand held can be priceless at times.

I really think the two have separate purposes. I think having both would be the ideal thing. I love my 24-70 and have taken great shots with it. It takes great low light photos as well as portraits. But, having IS is good when you are hand-holding & stopping down.