random rom'd X
I don't think you'll need to overclock it out of the box, it's already running faster then your D1 (dual core 1Ghz vs 550Mhz) and looks pretty responsive in the videos out on it... Of course it will be fun to see just how fast it can go.
There is no comparison between the Bionic and the OG Droid.
Even if you're OC'd to 1.1Ghz you're still running a 2 year old chip that only has 128MB of RAM vs. a current generation Dual Core 1.0Ghz CPU with 1GB of RAM. It's night and day.