I had the 17-40mm L as well as the 17-55mm. The 17-55mm stayed on my 40D all the time. Eventually, I used the 17-40mm on my 5D MK II, but while good, it just did not seem to be that good, so I sold it and bought a 17mm prime and a 35mm L.


Unfortunately, I found that after buying the 35mm L, the 40D just gathered dust so I sold it and later reluctantly sold the 17-55.