This all depends on what you are looking for ina docking solution. If you want to keep desk space availbe then I would say go for the on end solution such as Byte-dock or Hengedock. However if you want to run multipule screens as in the macbook screen and the external monitor this will not be possible with an on end dock as the macbook will have to remain closed. So you only option would be a bookendz dock that I can see.
I have read a bit about these Byte-docks but I cannot pass judgement yet as they are not out for a little while yet (according to the website).
Henge on the other hand have been around for a while now. I think at least 18 months, and I have some good and some bad points about them. Good point generally go on cost and easy of use. However I also read that the plastic in the bottom of the dock (while the plugs come through) snaps causing loose connections and because of this poor video output etc to occur, and while they advertise that the dock is cheap by the time you add everything else on like the cables, delivery, construction time it all adds up to a headache, and works out around the $200 mark.
Bookendz have been around for years and are still going strong that should tell you something, but it all comes down to you and what you define your requirements as.
Hope I have enlightened you to your options some more with this comment..