The 183 is a known quantity at this point. The amp glow can be a little variable and may not calibrate perfectly every time...although note that my 183 is uncooled, so you should have more luck with the cooled version.
There's not a lot of doubt that the 533 will prove to be a solid performer.
Besides the amp glow, the other main pro/con between the two is the pixel size. The 2.4 micron pixels on the 183 like light...expect to take longer exposures with the 183 than the 533 (which has larger pixels).
Oh and you can't bin a colour image in the same way as mono CCDs. Each "colour" pixel is constructed of a cluster of 4 pixels, 2 green, 1 red and 1 blue...so if you bin 2x2 you end up with a single black and white pixel. You can, of course, resample the image down after you have processed it
