I wouldn't say Dells are poor on quality. They use some well-known stuff like Nvidia video cards, Samsung ram, Hitachi hard drives, Lite-On, Biostar motherboards, and they still run much quieter, almost silent, compared to what I build. My computer sounds like one of those window unit air conditioners with its (3) 80mm/2500rpm fans.
Besides, at the rate that computers are progressing, I find myself getting a new system every 2 years or so. It's a cheap solution. For what the general public uses a computer for, they don't need some hardcore overclocking equipment, and I doubt they'll even know how or even know what overclocking is.