I am planning on purchasing the 70-200 f2.8L when I pick up my 40D, The question is, Is it truly worth the $500 for the IS. I generally have a steady hand and do 95% of my shooting without a tripod. I have both a 28-105 non IS and a 28-135 IS lens and do not really notice the difference between the results. I have shot as slow as 1/20 without any problems hand held. However I can see with a zoom greater than 135, the IS would be useful, especially in the low light situations.