Yes! I do have the 70-200mm f/4 IS! It has worked very well for me, and have used it very successfully for portraiture. I mainly use it for event photography, for getting in close to those candid actions or expressions coupled with that beautiful background blur. I’ve attached a recent example taken with the f/4. It’s obviously not as good as the f/2.8, but it works well.
The main reason I have the f/4 instead of the f/2.8 is because of weight. I use it a lot hiking in the outdoors where weight is a big deal, and where I seldom want anything less than f/4 anyway.
However, I’m thinking about purchasing a f/2.8 for use at events like weddings and conferences where there is a lot of indoor shooting. Every time I shoot an event I wish I had a smaller aperture than f/4 at 200mm. That’s why I would never consider the 55-250.
But, back to the real question . . . about IS. I would say, yes, it is worth paying extra for it. Lenses will last a long time if you take good care of them and if there are no accidents. With IS and my steady hand I feel comfortable shooting at 1/80th, and even 1/60th sometimes at 200mm. If I didn’t have IS, I’d feel pretty limited to 1/200th, maybe 1/160th (see attached). But then again, most of the time I’m being paid to shoot these events so I am much more willing to invest in equipment that will allow me to shoot in darker and darker situations, thus providing better, less grainy shots for my clients.
