About 21 percent of iPhone 4S buyers are opting for the top-end 64GB model, despite a $399 US pricetag, a Consumer Intelligence Research Partners survey suggests. The group recently surveyed 365 people who bought a 4S during the December quarter, narrowing down candidates from an initial range of 6,316 respondents. The 4S is the first iPhone to have a 64GB option instead of just 8, 16, or 32GB.
