After a couple of high-profilereports about how the plastic iPhone isn't faring too well in the laser-cut shadow of the iPhone 5s, here's a bit of evidence to the contrary. It comes courtesy of stat collectors at an app marketing platform called Localytics, who claim they've spotted a distinct upwards trend in the number of Americans using a 5c relative to a 5s. Whereas usage of the flagship metal iPhone was 3.4x higher during the launch weekend, this ratio has drifted down to 1.9x one month later, suggesting that a secondary wave of not-so-early adopters is happy to give the cheaper model a bit more consideration. Of course, these ratios don't tell us anything about absolute sales figures for either handset -- we'll have to wait on first-hand info from carriers or from Apple itself (perhaps as part of today's event) before we know those.