Shifting from the personal towards something representing more?
Sydney,
The 70-200 lens, whether by Canon, Nikon or any other modern lens MFR serves to reach out at a good distance and flatten the subject, rendering backgrounds less important and bringing attention to what one chooses. This particular lens is at the second rung of brilliant 35 MM Eos lens but gives no barrier to producing stellar images. It's lightweight and can fit in a purse or ample pocket, a perfect traveling lens. The x1.4 convertor extends the range by 40% and that extra reach is often all one needs together with a 35 mm or 50 mm lens to shoot almost anything from sports, to scenics or models and portraits.
With this lens, as long as you point it at your subject in reasonable light, your picture will be perfectly in focus and well exposed, so the lens, as usual did well. So I'd invest in the 70-200 f4 IS. I actually own the f 4.0 L, non-IS version, and it works as well as my more expensive 70-200 2.8L IS. Used, non-IS, versions of the lens are really worth hunting down as they are excellent performers and less expensive.
Asher