Saw this and thought I'd throw my recent experience in here:
Wanted the 100 for the form factor, but finally sprang for the 500 due to the built-in webcam. At the local VZW store here in NYC, they only had the 100 in stock; salespeople didn't even know the 500 existed (wtf?). One guy spent 3 days last week tracking one down for the $249 Verizon-advertised price. It looked like a Paramus, NJ store had one, but when it didn't arrive after 3 days they pleaded 'inventory glitch' ie. they never had one to begin with. Then the word was "they discontinued manufacturing the 500". So I was forced to go out to Amazon and pick one up for the full $349 currently listed (I thought the initial posts I saw about a $149 Lapdock 500 were typos!). Finally got my mitts on it; loved it so much I went right back to the VZW store and picked up the 100 after all, albeit for their current $180 price. So, I've spent roughly half a grand on these two gadgets. I like them, but I can't help feeling a twinge of regret not being aware of these Lapdocks sooner when the prices were evidently much lower (and availability was somewhat more predictable). Anyway, if and when they finally roll out the fw to make the Droid 4 'global' ready/capable, I will be one happy clam.