but itÂ´s not parfocal (same as the 70-300mm L).
thats not so good for spotting.
Course it is ;-) it's called autofocus !
Seriously though, I'm not familiar with lenses that are parfocal, so what I haven't had I never miss... Whilst it's easy to dismiss a lens because of a single feature, many of us don't have the disposable income to invest in lenses that cost as much as the 70-200mm f2.8 IS, let alone the longer fixed primes, regardless of how much we would like to. It's easy to take a X is best approach, but the reality is that practically all purchasing decisions in life are a financial compromise. Personally, I don't use my 70-300mm that much, so don't feel a strong urge to get a better lens in that range, I'm more of a wide and/or low light photographer, so I'm starting to expand my collection with that in mind, the 70-300mm was bought at the time I got my 450D about three years ago, the 15-85mm last autumn, the 50mm f1.4 a few weeks back, I'm now pondering wide low f, the 16-35mm would be nice, but I suspect the 28mm f1.8 might be all I can justify, maybe a 17-55mm at a stretch... Watch this space, but gawd do I want Canon to do some wide fast EF-S primes !