My vehicle has an instrument cluster display in the dash (on the sides of the speedometer) of the vehicle which displays road names, speed limits, etc. Will this feature be retained when upgrading to Sync 3?

Unfortunately there are some incompatibilities with Sync 3 and these instrument cluster displays. Depending on your vehicle and the firmware version for these displays you may lose these features and only a compass will be displayed (or this information may only be present when you have an active navigational destination set)