Canon 1DS and 1DMKII re evaluating image quality

Originally when I got my Canon 1DS MKI I was not impressed with images taken at iso's higher than 250, too much noise.
Recently I was contracted to shoot a wedding under heavy shade, went to the venue and did some preliminary test shots at iso 1250. Needless to say the images looked like crap. That evening I posted some questions in a forum asking how I should handle the low light situation outside in the open, this is very different to handling low light inside a room.
Someone suggested I try iso800 on my cameras, I did, processed them with Adobe Lightroom and was very impressed with the results, more on this later. Looks like my cameras will be good enough for another 2 years or so, saving me MEGABUCKS .