I use the EF24-105L, the 10-22 EFS and the 100-400L. All very good lenses. Next on the list to purchase is the 5dMk2 and the 70-200L f2.8
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I have to say... the optics on the 24-105L f4 are fantastic and it's a brilliant lens for the majority of uses. I know a couple of people who have the 24-70L f2.8 and they wish they had bought the 24-105. You just don't get as much benefit out of the extra stop as you do out of the extra reach... and the extra stop can easily be compensated for by using a slightly higher ISO. The 100-400L f4.5-f5.6 is a great lens in bright light but is a little soft beyond the 300mm mark.... Plus it's rather heavy and is a pain to use for any period of time with the lens hood on the front. I don't use it as much as I thought I would and I suspect I would get far more benefit from the 70-200L f2.8 IS.
The EFS 10-22 ultra-wide is a great lens on a 1.6 crop camera but can't be used on a full frame one. I tend to use this one sparingly as well, but it is good for landscapes and also for getting nice wide shots of locos.
Hope that helps anybody who is thinking of buying one of these lenses.
You can check out some of my more recent photos on my Flickr page... Feel free to leave comments and thoughts. All comments and criticism are welcome
http://www.flickr.com/photos/24731347@N07/