Summary: The printed output from the x543 is great. Crisp, colorful - exactly what I'd hoped. And, it's reasonably quiet. Double-sided printing works perfectly (though it does slow output). Contrary to what the previous reviewer said, I am offered the option to print double-sided on every document, in every application. (And you can buy the toner right here on Amazon.) However, the scanner is a nightmare.
Summary: Nothing wrong with the printer, produces nice quality copies, scans well and is very quiet... but it took me six hours to set up. Firstly, I'm IT literate and have a good range of printers so it isn't just me. Getting the printer out of the box and removing the various packing tags was no harder than usual (although the printer weighs 25kg so is not easy to move), but software installation was a nightmare.