After the Droid Bionic recently received a rather big update (version 5.5.893) at the beginning of this month, we were all wondering about the undocumented mystery-update with numbers 5.9.901 that surfaced yesterday.

It turns out the update is nothing you want to ignore! As with any major refresh, it contains application updates and improvements (like VCast Apps Store, Sling stub application, MOG stub application, YouTube fixes, etc.), data connectivity fixes (referring to situations where phone is stuck in 3G mode in strong 4G coverage, no 4G data connectivity, improvements in Wi-Fi Mobile Hotspot LTE download performance, etc.), device operation improvements (support for Bluetooth Personal Area Networks, missing SMS alerts while on voice calls, choppy audio while streaming via to a TV via HDMI, no Bluetooth audio when paired and connected, etc.) and stability/performance improvements (resets after camera multi-shots are taken, clock widget time does not match Notification Panel time, etc.).

Source: Droid-life