So I just got done ordering my first Canon products, but due to the holiday I'll have to wait until Wednesday to get them. I've been shooting Pentax for the past few years and absolutely love them, I have the full frame K1 and a crop K3. I mostly do wildlife and the lack of new long fast lenses is what made me look at Canon. I'm shooting with the Pentax DA560 F5.6 now on the K1 and its great but that's all they had, no 400/2.8 600/4. So I just ordered the 600/4 from B&H and will probably sell off some Pentax lenses and then add the 400/2.8. I will definitely be keeping the smaller focal length glass though and the K1. I've found this forum through the Pentax Forum and hope it will be as big a help to me as they were, I'm still very new to photography and learned so much from them but now I have a new system to learn. I downloaded the user manual to study up on until the new stuff arrives but I'm sure I'll have lots of questions.