oh so many replys..

i have to read them all but to the ones i have read:
my longest lens is the 70-200mm F4 IS and it is the only EF lens i own right now.
it was a present from my boss (my wife) on my last day at the job.
i knew i would definately want that lens. because it´s lightweight.
i also used to shoot a lot in that range with my trusted T90.
as much as i would love to have a 400mm lens with me, two things speak against it.
1) my wife. she said one camera and three lenses is the maximum.
2) has to do with 1. i don´t want to carry so much camera gear with me on the trip.
the EF 100-400mm would be a great choice maybe, but it´s to big and heavy.
i thought about the EF 24-105mm F4 IS (or EF-S 17-85mm 4-5.6 IS) and a ultra wideangle as second and third lens.
i also thought about buying a teleconverter.
is the canon 1.4x really worth twice as much as a kenko 1.4x teleconverter?
i do see where the 5D Mark 3 is better.
i guess the info about the AF system takes more pages then the whole manual of my T90.

the build and handling is fantastic, no question.
i just thought with all the stuff i read about FF vs. APS-C sensors that i would immediately see a difference in image quality.
keeping both cameras is not a bad idea.
i could give one to my wife.

she bugs me with "hey look over there... hurry take a picture" anyway.
thx for all your replys.
i hope you understand my english, im from germany, so please excuse that it is far from perfect.