Can anyone comment on the general sharpness/IQ of the f4 non IS, thinking about picking one up in a few months as they are only ~$700, the f4 IS adds ~$600 which basically makes it a no-go.
Is it an awesome zoom for that price?
Is a tripod necessary for a lot of shots with a non IS?
It's decent... but it's at the very BOTTOM of the list when it comes to sharpness (below even the f/2.8 non-IS). In this case you do get what you pay for. The f/4 IS is leaps and bounds better than the f/4 non-IS.