Hey Folks, Last November i got myself a Canon 550D body and a few 2nd hand lens that each were under £50 at different focal lengths. After 8 months i finally got a brand new Canon 24-70 L and only 2 weeks ago i snapped up a Canon 300mm L F4 USM (Non IS). These focal lengths satisfy me though I'm likely to be wanting a 70-200 F2.8 L IS USM to fill my middle handholding needs where the 300 is too big (It needs to be on the tripod), and the 24-70 does not have enough reach. In addition i will be looking for a 16mm and a T+S lens for better photographing buildings. I have a vast interest in photography from animals and birds to buildings and landscapes. What i am noticing more is my little 550D preforms poorly in low light and after a poor attempt at getting rid of some dust on my sensor i seem to have nocked the focus light off since it no longer shows up in the view finder (I am glad i messed up a cheep camera and not a expensive one). I had got the 550D to experiment with and see if i could break it, i would rather break a little cheep one than a £2k+ cam. Now my needs for a upgrade are: Excellent low light focusing performance Better dynamic range Sharper images with less grain past ISO 1600 Weather sealing (I believe both my L lens have some or full weather sealing) It to be under 1 Kg or able to balance the 24-70's weight which is very forward heavy on the 550D Under £3000 So i've been looking at the 5D Mk2, the 7D, and the 1Ds Mk 3. Or wait for a future body. My biggest question is will ether of these really improve my noise issues at higher ISO levels and even at lower iso levels i can often get noise at iso 100. The other thing is will i get better focusing performance, the 550D often searches in low lighting conditions forcing me to manual focus.