If the price of the f/2.8 version is a barrier, then this new f/4 model, despite its failings in some areas, is actually a good alternative, especially since it adds the benefits of the Image Stabilizer. However, the long-running EF24-105mm f/4L IS USM lens is also worthy of consideration. The extra focal range from 70mm to 105mm may well prove useful, even if you own a 70-200mm lens, having some overlap means you do not have to switch lens quite so frequently. If budget really is a concern, then it is also worth looking further down the Canon range. Even then often forgotten EF28-105mm f/3.5-4.5USM lens manages a DxOMark score of 17, but for substantially less money because of the lack of an IS motor and the variable aperture.