I see that the biggest complaint many seem to have about this camera is the noise above ISO 200 but I have say that coming from Nikon the Canon 1Ds has less noise at any ISO compared to my old D1, D1x and D100 hands down. Prints at ISO 1250 from the 1Ds are still very usable.
As for dust on the sensor, my feeling is that any DSLR is going to have it's issues regardless.
The resolution and detail this camera produces is amazing. Better than 35mm film by far.
Everyones needs vary and this camera may not be for everybody.