Q: OS X Startup Slow- Loading bar and wait

Are you sure that you are using OS X Mavericks? To my knowledge the only system that uses a loading bar at startup is OS X Yosemite Beta, and thats slow as its a Beta and not complete. Hope this helps

If you are on Mavericks or earlier, your computer is starting in safe boot because of a problem.

Safe Boot takes longer than normal startup

Troubleshoot your software.

Isolating issues in Mac OS X

Resolve startup issues and perform disk maintenance with Disk Utility and fsck