Woth it? It depends, The HD dock has a micro HDMI output, 3 usb ports, & a 3.5mm jack out & power input. You can hook up a wired keyboard & mouse to the dock, HDMI out to a tv, plug in your bionic & get webtop on the tv. I used this setup on a trip in a pinch to remote into work via logmein. You can also charge your phone.
You can use the mirror mode if you just want a big bionic screen, or view pictures & stuff like that.
I think there is a webtop adapter that is like $30 that will give you the webtop without the usb ports. (use a bluetooth KB & mouse)
If you just want to charge & have the bedtime/productivity mode the standard dock will handle that. (the HD dock will bring up those modes also)
It really depends on what you are looking to do with your bionic.
I hope that helps a little.