If you came from the Droid 1, you would be more comfortable with Bootstrap, because it feels the most like CWM for the Droid.
If you are more familiar with the safety of the Droid 1, you will like Safestrap.
Bootstrap has no safety net, if you enjoy SBF/FXZ files, this is for you. If something goes wrong with your ROM, and can't get back to Bootstrapper, SBF/FXZ is the only way back.
With Safestrap, you have 2 "systems." One being your "stock" non-safe system and your "ROM" safe system. It installs a splash screen at startup so you can always make it in to CWM. If something goes seriously wrong in safe mode you can just go back to non-safe stock and start over!
My guides below are for Safestrap on D3 but they are mostly universal for D3 Bionic and Razr.