I went to the VZW online store to take a look at the different lapdocks. I came across 3 different ones:
Lapdock for Bionic
According to Verizon and Motorola the Lapdock 100 is compatible with the Droid Razr, Atrix 2, and Photon 4G. The Lapdock is compatible with the Droid Bionic. And the Lapdock 500 is compatible with the Droid Razr.
Lapdock 100 Factsheet
Lapdock 500 Fact Sheet
VZW pricing is: Lapdock 100 = $199.97, Lapdock for Bionic = $249.97, and Lapdock 500 = $299.97.
What a reviewer wrote:
The 100 has a smaller battery (5 hours) and cannot charge the phone from its internal battery. The 100 has a thicker case that houses a better set of speakers, and a bigger keyboard that does not have the chiclet style keys. The 100 has a better system for holding the phone that doesn't require the case to be removed, consisting of a stow-able cable that connects to the phone, and a slot that is lined with a no-slip gripping material. The 100's keyboard is larger and has a number of dedicated keys that correspond to those at the bottom of the Droid's screen (home, search, etc.), the 100s thicker case allows for a bet set of speakers as well.
The Lapdock for Bionic and Lapdock 100 seem to sport the same 10.1" screen but the Lapdock allows for 8 hour charge compared to the 100's 5 hour charge. The Lapdock is older while the 100 is newer as well as the 500. From my perspective the Lapdock for Bionic and 100 seem more like a netbook while the 500 is more like a notebook as it carries a 14.1" screen, full size keyboard, and webcam. The Lapdock 100/500 both use an extended cable which would be great for those who have cases. I would prefer the 500 myself but whether it's compatible with our Bionic is a different story.