Originally Posted by morbot
The other big benefit, especially for mountain bikes, is finish durability, according to [Pioneer Metal Finishing Engineer] Haasch. “Paint is very susceptible to scratching, whereas anodizing, because of its hardness, is very difficult to scratch or scuff,” he says."
IMO, andoized finish scratches down to bare metal easier than paint, but little scratches/nicks in an anodized finish are less noticable than scratches in paint...but YMMV