Have they changed the keyboard backlighting?
I have a small, but annoying hardware problem with my D4. VZW keeps sending me a CLNR and the keyboard backlight on it is dimmer and more yellow than mine. This CLNRs have other obvious problems, but the keyboard backlight is the first thing I check before bothering to peel the stickers and there's an obvious difference.
Personally I refuse to accept a replacement that is in worse condition than mine that is about three months old and in practically new condition. I feel like they get these defective phones in, throw on a new shell, and send them on out without actually doing a full QA check. The reps at VZW tell me these come directly from Moto after going through a 100 point inspection; sounds like someone is getting lied to.