It's really about the scanners and the software. C41 could be challenging for some scanners and software, but for example, the Pakon turns out the nicest colors for them (35mm only) because Kodak spent a lot of resource to get it right. The Pakon is a minilab scanner and they are built to make most consumers happy without work from the operators.
Vuescan is a great piece of software and works well, but generally speaking, Silverfast can clean things up better than Epson Scan, Nikon Scan, and Vuescan, most of the time.
Now I use a Flextight scanner, and most scanning problems are no longer problems ;-)
Most films scan well, at least on latest scanners (which are all at least 10 years old technology anyway) and good software, and good operators.