I have the offer of a 5 year old canon 24-70 F2.8L for around £300. The lens was serviced by canon last year and is in very good condition. My queston is will the lens be ok to use with 40D or should I look to replace my current lens (faulty) 17-85 F4.5. I shoot a lot of Morris dancing and I am a little concerned i will lose out with the not so wide 24-70. Any help is appreciated